I have a 2014 Nissan Rogue and the a/c recently stopped blowing cool air. I took it to the dealer service department to have it checked and was told the compressor needing replacing. I left it to have unit replace. And next they called and said the new unit they installed was defective and they had ordered another replacement. My car was ready the next day. When I picked it up, I was told that they noticed a “spark” when hooking up the second replacement and further inspection showed a broken a broken wire, and that it was the broken wire that damaged the original unit, making it necessary to replace the compressor. I questioned whether simply replacing the faulty wire would have fixed the problem, instead of having to replace the entire unit, and was told it was necessary. They said yes it was necessary. They said the wire was probably damaged by something like a rock or other object hitting and damaging the wire. Does any of that make sense???.
No it doesn’t make sense. Your mechanic screwed up by replacing not one but TWO compressors and then finding the actual problem - a damaged wire. I am actually amazed that they TOLD you they found a broken wire. I suspect they know the original compressor was OK and they are trying to cover their tracks.
If you want to get your money back on the compressor, I’d suggest elevating the complaint to the Service Manager and then the General Manager at the dealership. And the manufacturer’s zone rep.
Be nice about it but tell the same story you did here and stick to it. Elevating things to the next level always makes life painful for those below. Make sure they know that is what you intend if they don’t address the issue. If they offer to split the cost, I’d take it. If they stick to it, gently tell them you can take them to small claims court and you’ll tell your story to the local media.