Had a guy round to fix some paintwork on my car. Dog loves people, wants to play with him- for some reason she took a massive liking to him. I put her behind the safety gate, she jumps over. I ask if he is ok with dogs, he says yes, and bends slightly towards her. She thinks he wants to play, jumps up at him, scratching his arm. I put her back inside, he goes to look at the car, asks where the dent and marks are-even though he said they were clear from photos I sent. He suddenly says he doesn't feel happy about doing the car, his arm is too sore, he needs to make a doctors appointment, and off he goes. I later get a text from him, saying if I want to do the right thing I should pay him £250, the price for the paint job that he hasn't done. What do I do?