My last dealing with a trans shop was a rebuild on a 700r4 in a 87 Vette I had. It failed after about 18 months and 9k miles of mild driving. I carried it back to the shop and an aluminum drum had broken and taken out the tranny. No fears, the shop rebuilt the tranny again, upgraded the aluminum part to steel, and charged me the full price...again. I went ballistic. The "warranty" was one year or 10k miles. Yes, the warranty's time was up, but a part failed that he should have replaced with the upgraded part the first time and the mileage was under. He refused to help me any at all with the bill. This was supposedly the best shop in town.
Since that, if at all possible, I'll do my own work. It may take a while, but it isn't rocket science.