Auto Tech

I took my car to Auto Tech in Lansing after it started running rough. The diagnosis was that I had slipped the timing chain and trashed the valves. So I had them put a used engine in it. It took them twice as long as they stated to get the job done. $1700 later, I get the car back and it won't idle at all. You take your foot off the gas and it dies. I took it back and they have had it for over a week and can't fix it. They now want me to take it to the dealership to have the pcm reprogrammed. I don't have much hope that this will fix the problem. I am sorry that I ever took my car to this shop.