Timing belt went and ruined engine in 2003 Audi Quattro. Whose fault?

I took my Audi to the dealer so I would get service and advice on how to take care of it. I can't get an answer as to when the timing belt should have been replaced. Some dealers say 7 years into the vehicle. Some say for the 2003 it was originally 75,000 miles but got changed to 105,000 miles. Some say it could be warrentied from original manufacture due to all the timing belt issues and class action law suit. I had my car into the dealership at 72,000 and they put a new transmission and front axle in for $5400. I just had it in the shop again in November for the check engine light at 76,000 miles. They said the engine light was due to a temperature gauge problem. So, if the timing belt should have been replaced at 75k then I would have expected them to tell me and take care of it on one of those visits. If the repair was changed from 75 k to 105k, why didn't it last? Any advice/information welcome.

I agree. they should have advised you of the belt at the mileage interval but they did not. They cannot be held liable for that. The responsibility still falls on you to get the service performed. You can appeal to audi customer service about the dealer and there lack of recommendations and they may offer you something but they wont take full responsibility for the repairs. good luck Roy