I have used several different branches of ATS over the years for exhausts and tyres etc. and have found them excellent in dealing with things on the odd occasion when they go wrong. For example, I had an exaust that started leaking when it was two years old and ATS replaced it immediately without quibble. I believe their exhausts usually have a 2 year guarantee so you should be OK on that score. The problem in your case is that you took it elsewhere for repair. It is worth speaking to them and stressing that you had to get it fixed and they had given you incorrect informatioin on opening times. If they are not prepared to compensate you then you would have to go down the Small Claims Court route. Good luck and please let us know how you get on.