If I understand correctly the stealer has turned your rotors THREE times??? Its hard for me to believe that the rotors would still be within spec (too thin) even if the turnings were light. If possible, you should be there when they throw the mic on those puppies. I'll bet they are out of spec by now. If the stealer has replaced your rotors at some point then, as others have pointed out, you should keep an eye on the rear brake adjustment.

It has been my experience in the automotive world that once a rotor warps it should be tossed. Turning will provide a temporary fix but it will warp more easily since it is even thinner after turning. I've had excellent results turning rotors that were mildly scratched (but not causing shimmy) and reusing those. But never with warped rotors.