I recently bought a car with a three-month warranty. After purchase, a number of defects came to light. The dealer from whom I bought the car agreed to put all of these right, but it took several weeks for one part that needed to be replaced to be supplied, and I was deprived of my car for a month.

Once the car had been returned to me, it became apparent that two of the repairs that had been signed off as having been carried out had not, in fact, been done and another fault also became apparent. The dealer has agreed to rectify these, which will mean returning the car to him for a further period.

I have asked for a new warranty, as the original is about to expire within the next week and I would like some surety that the repairs have indeed been done, and done properly. As I did not commission the work, I have no invoice - my only proof, such as it is, is my own typed list of issues with his additions saying 'repaired' or 'replaced' beneath each item. He says he cannot issue a new warranty.

Who is the more reasonable party in this matter and do I have any rights in this regard?