I've had a simular experience. a simple tune up ended up costing more than $400.00. After hearing your story, I think I got off cheap. The next year I bought the parts and did it myself. There is a reason B.O.A.T. means bring on another thousand. I had another experience on my truck $3000.00 dollars in repairs, and it took them 4 trys to fix it. ...Or buy a new truck for $30,000.00, or another used one that was sold for the same reason, and still needs the repairs.