Go back to the shop and tell them to fix the problem or give you your money back. If they drag their feet, contact the better business bureau. You need to document all the things you are doing. There needs to be a paper trail, showing that you took exhaustive measures to resolve the problembetween yu and this shop, if all else fails, take them to small claims court. Before you sue them, either hand deliver or better yet send certified mail at least two letters threatening a lawsuit prior to filing suit. That way you can stand in front of the judge and say, "Your honor, I am very sorry to be taking up the courts time, I made many attempts to work this out before coming here." You already have about as much into repairs as the car is worth