With regard to Lizzie Enfield's Signal Failure (September 25), I should like to apologise to Graham for the unsatisfactory responses he has received to his letters of complaint about train service difficulties he had experienced.

We have in the past been guilty of failure to address specific issues raised but this situation has been addressed and the problems resolved.

On some occasions, a customer may receive a standard letter from our chief executive officer which explains the circumstances relating to an incident that may have affected many people.

But any specific points covered will be addressed in follow-up correspondence on a personal basis.

It is our policy to investigate fully and respond in detail to specific issues raised by our customers and, if Graham would like to let me have further details, I shall willingly follow these up with our customer service centre.

I should like to point out, however, the vouchers he received as compensation may be exchanged for purchases at five wine chain-stores as an alternative to public houses and restaurants.

We offer these as an alternative to rail travel vouchers and they have been very well received by customers.

-Deborah Pester, Head of Communications, Connex South Eastern