I have a mechanic putting a rebuilt motor in my car. He picked the auto up 02-14 and drove it away. I paid $200 when he picked up the auto paid for the rebuilt motor on 02-26. He has not delivered me the car running. The place where I bought the motor says the motor is good and he says the car isn't not firing. They want to test the motor and he hasn't taken the motor and the warranty will expire 08-26 and he wants the balance owed and hasn't delivered finished product. Please advise.