At this point I agree with those who have spoken up already. Give the shop yet another chance? I don't think so.
Try to get a recommendation for a shop in your area, and get tuff with the insurance company if you have to. Somebody there will have a sympathetic ear. Try saying, "Put yourself in my place. Wouldn't you feel frustrated?" I always try that to get buy-in from whomever I'm talking to. It's sort of, "Hey I'm a human being--you're a human being, let's support each other."
Good luck; I feel your pain.