So a couple months ago my car is running great other than an alternator belt coming off. I take it up to the shop to have a new belt put on and decide why not get the oil change while I am up there. I pay $66 and they give me the vehicle back. Take this story back 2 weeks before the radiator hose sprung a leak and kept dumping out a ton of water on hills and shit (kept filling it with water till I changed the hose). Now after I received the car back I took it 2 towns over which is 30miles or so. On the way I noticed the car was smoking out of the exhaust a little more than usual but i thought it was just the new oil. Well then we stopped at the mall and afterward got on the interstate on the way back home and the car cuts off completely at 65mph and comes to a stop smoking (engine). Called the guys that changed the oil and got them to come out to tow me. My conclusion was that they fucked the oil up when changing it because it had been running like a champ. Well they didn't give me a price that night for towing but said the next day they would diagnose the proble. Said it was the water pump and said i needed to fix it. I bought a new water pump and they installed it. Told me it was still over heating and needed a thermostat. By the time I bought the thermostat they said it was ether a head gasket or the heads warped. So at this point they have diagnosed incorrectly and still do not know the problem. Today the guy comes over to my house 3 months later saying hes gonna take me to small claims court about the $350 bill since I am not paying for it since it still doesn't run and he bullshitted me about towing and the problem. What should I do guys?