> He listed some vague reasons, compressor this, compressor that, costs, etc... which I didn't care to understand. wouldn't part of an "adult-to-adult conversa

> He listed some vague reasons, compressor this, compressor that, costs, etc... which I didn't care to understand. wouldn't part of an "adult-to-adult conversation" also be to try and listen to the other, if nothing else than to understand their arguments? > After some filler words, he said he will talk to the owner terminating the contract and giving a refund. I said great and hung up. If that's what OP understands as "negotiating the difference" then ok, I guess...