Front Seat Belt Buckle Assembly problems of the 2004 Volkswagen Jetta

My 2004 Jetta has 51,000 miles and is only 3. 5 years old. The air bag/ seat belt alert icon came on and I brought the car to new country vw in greenwich CT. I was told that the passenger seat belt latch failed and needed to be replaced. I was charged $140. 00 for this visit and was told that the repair would cost $425. 00. They stated that the part was on a nation wide backorder and they did not know when the part would be in the USA. The fact that there was no part available in the entire us indicates to me that there is a problem with this part. A critical safety component like safety belts should not fail after only 3. 5 years and should be excluded from any limited warranty. Also because of this parts failure I was told that the air bag system would not work properly, which is another safety issue.