Replace Exhaust System

In April 2010 Bomar indicated that my 2000 Chevrolet Cavalier needed to have its exhaust system replaced. I agreed to let them repair my car. The cost of the exhaust system replacement was approximately $1,000. Approximately 2 years later when I brought my car to Bomar for inspection, it indicated that I needed my muffler replaced. I was surprised by this since it was 'supposedly' replaced 2 years before. However, I allowed them to replace it. In November 2012 (6 months after the muffler was replaced and my car was inspected), the muffler separated from the exhaust pipe in front of it. The pipe was rusted through to the point that it is hard to believe that it passed inspection 6 months prior. I allowed them to replace it at a cost of $200. In January 2013, I heard a loud noise in the front of my exhaust. At this point I took it to Chevrolet Vehicle Repair. Chevrolet indicated that the front of the exhaust (including the catalytic converter) needed replaced and that the original parts were still on the car. That is, Bomar never replaced them. Chevrolet replaced them at a cost of $900. You hear about nickel and dime mechanics ripping people off because they don't know how to repair something but this is the first time I ever heard of a mechanic charging for replacing parts that they didn't actually replace. The sad part is I really have no recourse other than to report them to the Better Business Bureau. After all, I can't prove they didn't do the work. My advice - STAY FAR AWAY FROM BOMAR