Sisson Pre-Owned

My husband financed a car from Sisson on December 17. The car has been in the shop ever since, with shop trips starting in January and ending on July 27. I finally got my car back claiming it was fixed; the car is still not fixed, and Sisson is refusing to give me my money back. They agreed to pay to have the engine fixed. I got the car back and it is still not driving correctly. I was told they will not give me my money back and I should pay to have the computer taken out and replaced. I have made 7 car payments on a car I have driven maybe 15 times. I paid 24,000 for a car I cannot drive, and they made me pay 3,000 for a warranty and the warranty company dropped me because the car is modified!