My GC won’t accept final payment?

I hired a GC back in May to redo my bedroom, closet and bathroom that were flooded due to the freeze and burst pipes above this area and replace carpet in living room and halls. I was given a bid by GC and agreed he’d do the work, nothing was signed and I agreed to his bid and price. The job took way too long and he had to redo quite a few things more than once, he would tell me he made a mistake on his bid but then would say but I’ll have to eat the cost. He was not a nice person to deal with at all because he’d choose tile without asking and had to take it back and blamed me even though he didn’t ask what I wanted. Work took May-Aug and had to continue to ask each day if he was coming back to finish the work. Finally the room was done and we were moving on the floors, well the bid did say carpet and I told him I’d pay the difference to do laminate flooring but then he said no you’re going to have to pay for all supplies for the floors and I told him no per your bid you included carpet, padding and installation. After a very heated argument I decided and told him it would be best for me to just pay for the work that was completed. He told me he’d have to go over the numbers and I told him I subtracted the amounts for the carpet he listed on the bid, he said he needed time to look at the numbers and redo the cost and I told him if you need to do that for you that’s fine but I’m going by the bid. After over a week not hearing from him I reached out and told him I had a check for the difference, he came by and attempted to give me additional paperwork with a new amount that I owed him, which was pretty much the entire amount i owed him. I told him no we agreed on the first bid and here’s the check (I did put final payment on it) he yelled and threatened me that he could just come back and take apart my room and I told him I’d call the police. Well this GC, who is actually not even a licensed GC or has an actual company is friend of my ex so my ex said he’d talk to him and give him the check. Now he won’t accept it, saying I owe much more. I’m being fair by just deducting from the bid the work that wasn’t done. What can I do in this case? I just want this done, the work wasn’t even done all correctly either and I’m not even deducting for that either. From what I’ve read he can’t file a lien which he has threatened me as well. Am I just a sitting duck waiting to get sued? Then I can counter sue for the bad work and the work that he didn’t complete? I also have a few recordings of our conversation that he says he’s only going off the bid. He never once gave me any additional paperwork with added costs of anything so how can he now give me a new bill. Any advice will help?