Injecting heroin into her collapsing veins every day makes Hannah Mayne function like the rest of us. The rattling of her bones judders away and the sickness in her stomach is quelled for a few hours.

But she doesn't want to live like this. With the help of her mother Kate she is trying to get off the drugs and stay clean. The frustration for them both is that the system makes their task so much tougher.

"Some people are born and just know how to live life, but I don't know how to do a lot of things that other people just know," said Hannah.

"Ever since I was young I've needed a drink to deal with social situations with friends. I had low self-esteem. I hated myself. Getting wasted was a way of feeling free."

Hannah has been in free-fall for three years now. Her parents had no idea how to cope at first but have since been on a steep learning curve to find the best way to help their daughter.

Kate said: "You are floundering around because you've never done this before and with an addict the goalposts shift all the time. You think you have got something in place but every day throws up a new problem and every day is the first day you have dealt with it.

"Your response is not always right but you aren't given any time to consider the options." One of those goalposts is her daughter's ability to access finance and a year ago Hannah agreed to accompany her mother and ask her bank, NatWest, to refuse her any overdraft.

A manager at the Churchill Square branch listened sympathetically and agreed to put a note on the system, which she showed Kate and Hannah.

Kate said: "What she wrote was quite painful but true. I went out feeling I had set up something that could prevent my daughter getting into debt and felt reasonably safe."

Another reassuring fact was that Hannah's entire income was made up of £70 a month income support and £160 a month disability allowance.

She felt sure no one would give an overdraft to a benefit-funded declared drug-addict but she was wrong.

A few months later Hannah was desperate for drug money and asked the bank for a £50 overdraft - they offered her £1,200.

Kate found out a few days later her daughter was £2,000 in debt and had gone to Birmingham where she promptly overdosed and was told by the hospital she would have died if a friend hadn't found her.

Kate was furious but was told by the bank Hannah had the authority to override the previous instruction, which was, in any case, no longer on the system because all notes are deleted after six months.

She said: "My daughter was drugged by a computer."

Infuriated, she went to the bank with Hannah to try to sort out a loan which would prevent her debt soaring higher with regular punitive bank charges.

The irony was that though a drugaddicted teenager living on benefits can get a large overdraft, she cannot be accepted for a loan.

When the bank then threatened to strip Hannah of her "assets", her mother thanked them.

She said: "Finally they were doing what I'd been asking for months. Her only assets were a dirty anorak anyway."

NatWest bank initially offered to waive the bank charges and allow Hannah to pay the overdraft back in £30 instalments but Kate refused, believing she had done everything possible to prevent the situation happening.

A settlement has now been negotiated.

The substance misuse services (SMS) in Brighton and Hove are a second source of grief for the Maynes.

They spent £20,000 putting Hannah through The Priory and find the statutory services complex and rigid beyond belief.

They are complex because there are so many acronym-filled agencies that a drugaddled teenager is unlikely to know where to turn without the help of her competent, articulate mother.

Hannah is dyslexic and can only cope with the forms required by the Rough Sleepers Team when their worker crosses out all the detail and asks her to sign her name at the bottom.

Then there is the rigidity of hours and access and time-keeping. The average addict does not keep a daily routine but many of the services they require are available only from Monday to Friday and from 9am to 5pm. Some open on occasional evenings or Saturday mornings but the regime does not suit the chaotic lifestyles led by Hannah and her friends.

Appointments are sent out by letter and by phone but addicts often have no permanent address or a mobile phone with no credit.

Then they will often wait up to three months for an assessment and medical before being put on to methadone treatment, which they must stick to consistently before detox treatment will be considered.

Kate believes it is a system of snakes and ladders - you get a few weeks along, only to miss a couple of appointments and be thrown off the programme. Back to square one.

She said: "The whole system is slightly punitive. They put the onus on the addict and say they will only get better when they want. But my argument is how do you know if you want to when the system is so difficult and the obstacles are so immense."

Hannah is despondent. She said: "I've got an assessment tomorrow and I really want to get into a residential rehab but I find it too hard to be expected to stay on a script of methadone and live where I'm living."

She said the methadone was not enough to sate her and addicts often end up "topping up" with heroin, leading to a double addiction rather than any solution.

Hannah said: "I want to go to Ark in Portsmouth so I'm not around addicts that I have used with.

"I hate and love Brighton. It's got a magnetic pull. I've left many times to get clean but always ended up coming back.

It's an easy place if you're on self-destruct.

It's easy to get lost.

"Even if you manage to get clean, people think that's the hardest part but there's so much work you have to do on yourself afterwards, change your way of thinking and behaviour."

The substance misuse services say they retain 89 per cent of addicts for at least three months but Hannah does not believe they remain clean for much longer.

She said: "The people I know are always in and out of treatment.

I don't know anyone who's got clean and stayed clean. They just have a few months off it here and there and then relapse again.

"It doesn't seem to be working."

She wants to make it clear there are many fantastic people working to help her. But she believes a system which gives recovering addicts a bed for the night next to a user and expects them to resist an environment saturated with heroin is not a good one.

She said: "I spoke to my friend yesterday.

She's been living in a hostel for a year and hasn't had one key worker session though you're supposed to have them once a week. They need more money and more help."

She said her hostel is one of the best in Brighton but is full of people with serious mental health problems, which the staff aren't qualified to deal with.

She said: "It just seems most hostels are just a dumping place for people that society wants to forget about."

Kate has tried to have her daughter sectioned at Mill View Hospital several times but to no avail. She said users take the drug to mask the pain of mental illness.

One time her daughter was admitted to the mental health wing after trying to commit suicide but was told she could not access methadone treatment on the first-floor detox wing so she ran away to find some.

Another time three policemen were called to her house and Hannah lunged at her mother with a glass in front of them, scratching and screaming at her.

The police sprayed Hannah with pepper spray but social workers were convinced 24 hours later that she posed no problem.

Kate feels she knows better than most of the health professionals what the reality of drug addiction is - she has spent the past three years shadowing two of them, Hannah and her boyfriend Ricky.

Ricky conforms to the usual addict stereotype - a boy abandoned by his parents as a baby, raised in care homes and who never received a single Christmas present until Kate bought him one last year.

Even though he has burgled her house repeatedly she has stood by him, writing a letter to the court recently asking that he be given treatment instead of a prison sentence.

He was jailed for 12 months.

Kate does not blame the system for her daughter's addiction.

She knows it comes from within Hannah, and her alone.

But she does wish her battle could be squarely with the heroin and not with the system supposed to be stamping it out.

National Drugs Helpline: 0800 776600. Consumer Credit Counselling Service: 0800 1381111.