general problems of the 2001 Audi TT

Purchased the car new in 2001, the airbag light started coming on intimately in 2003 had the cluster replaced in 2004 (15k miles) under warranty, shortly after it was repaired the airbag light came on again intimately for another 2 years until it stayed on permanently. I brought it back to another dealer they reset something and the airbag light went out again for about a year. In 2010 I brought it back to the dealer again for a cluster recall, they replaced the cluster all was fine then about a year late the airbag light came on again. Brought it back to the dealer and was told it was the airbag module. Spent $1500 to have the airbag module replaced ( think this was the issue all along). After having the airbag module replaced the seat belt light no longer comes on. Was told it is the cluster. The car has 37,000 miles on it this will be the 4th cluster in the car. The dealer wants $1500 to replace again with no guarantee. Audi accepts there is a problem and will pay a few hundred towards the repair. I will be responsible for about $1200, I have tried contacting the Audi manager (#248-754-3686) handling the case and my attorneys office has tried contacted them several times and they have refused to return any calls. I am without a seat belt warning indicator. I am concerned that I will have my grandson in the car and not know if his seat belt is properly engaged, or if my airbag is working properly. This has been a constant issue since I bought the car new and have put very low miles on the car, have always garaged it and never drove it in bad weather and the cluster remains an issue going on the 4th one.