We had a shop like this around here, the guy started pulling the same **** and well after 1500 bucks for a 3rd gen camaro exhaust( customer supplied parts due to the custom bending and shaping that had to be done for ground clearance) we got the car back and thats when we gave him the chance much like you are to make it right, he didnt make it right, his shop is no longer in existance and all his new ventures have failed on him due to this one incident with one customer.
Shut the guy down and remove him from the forum for business purposes.
