2000 Bravada window issues

I bought my bravada in August of last year and have had nothing but problems with it. The latest issue is that the driver's side window does not work. I have taken it 4 times now to have it looked at. I have had he regulator replaced twice, the rivets 3 times and the motor itself twice. I just got it back from the shop after replacing both the regulator and the motor again and rolled it down and was loving it. only to get home, roll it up and hear POP.

I talked with my mechanic and he said he can't figure out what is going on. he said I am snapping off gear teeth and he has no clue why.

Any help or guidance would be greatly appreciated. :screwy:

Matt