Does Audi has a recall for engine overheating due to faulty thermostat?

What is your question?

I had thermostat replaced once at 21000miles and the car was under warranty. After driving for two years, my car now has 52000miles. The car has the same problem but this this time the warranty is no longer covered.The Dealer wants to charged me for the repair. I just wondering if this part is still under warranty. Because its kind of hard to replace a new thermostat every two years. Or has some kind of recall for this issue.