Dick Wickstrom Chevrolet Will not stand behind work Roselle, Illinois

I have a 1999 Chevrolet Blazer that I brought to Dick Wickstrom Chevrolet (DWC) in April 2009 for service.  I had just purchased the vehicle with 84,000 miles so it needed rear brakes.  The service department fixed the rear brakes--rotors, pads, calipers, emergency brake--for the pricey tune of $980.00.  I have not had anyone else perform service on the rear brakes or do any other work with the right rear wheel of this Blazer since DWC did the rear brakes.  On September 10, 2009 I noticed a grinding sound in the right rear wheel area.  I called the DWC service department and they told me to bring the vehicle in that afternoon, which I did.  They took a look at the problem, called me Friday AM and immediately started to avoid taking the blame for the problem—their mechanic did not tighten the bolts that hold the caliper on so it came loose, bound up and grinded and caused a multitude of other problems as a result.  This is their problem should pay for all of the repairs.  However, the DWC service department said they would not pay for their problem—A POOR SERVICE DEPARTMENT THAT WILL NOT STAND BEHIND THEIR WORK.