Does anyone have problems with their porcelain veneers coming off multiple times?

My friend had 12 veneers put on and they seem to break quite often. I don't think they would be worth the money because they charge her 2,000 a tooth each time.

Yes!!? My dentist claims he is using white, top of the line glue. I have not even been biting anything! I can only cut up ALL my food. I'm at my boiling point. If I would have known this, I never would have done it. I had 6 top, front veneers made. I've had them for about 2 months and I have spent sooooo much time in the office having them remade. I'm always afraid of them coming off! Just went on a vacation family reunion and while brushing my teeth, 1 came off. My dentist recommended using vaseline to hold it in place, and remove it while I'm eating!!! Please offer some help and advice.