payne and sons contracting

Payne's was the lowest bid we could get. I argued that he was over $3000. too much but we had to have it done and allowed him to do it.
I told him I would monitor his time and multiply the same by his rate (which he gave me) Well it was $2,000 over one the main roof and
$700. for the sheds etc. In addition there was 20 sheets of roofing left over that he had stored in our garage. He told us we would get a sum back it turned out to be $1500. which we were grateful for but not enough in reality.
When the snow/ice guards where ripped out over the winter he was not going to put more ice guards in to repair it properly instead he was just going to purchase larger screws and install them. We were grateful for any thing at this point but he has never called to own up to anything. We are totally disgusted with him and his performance, At the conclusion of work last fall we asked that one of his helpers (sons) go under the two sides to the roof overhangs and retrieve the dropped screws as our power mower would be travelling there and we didn't want any flat tires. He sent two sons out and they retrieved 4 or five screw. My wife who is more mobile than I went behind them and picked up 56 screws they left there after they departed the job. When I called he said he couldn't depend on his sons. Never said he was sorry or how he could make up for it.