catalytic converter

He put the wrong catalytic converter on my vehicle and then even argued with the dealership that the it was an adequate part. He said there was a two year warranty on the converter but then claimed that the warranty was void after only a couple of months. The the local dealership tested the converter and told Harold that it was working but not perform adequately for the vehicle. Harold then told me that he would replace the converter with another one (which was to be the same as the one that was inadequate) "just to get me out of his hair and then he was done with it". When he was asked to refund some or all of the money he said "that's not gonna happen!".