I'd tell him that this problem is still not resolved, and he's had plenty of time. If you don't have your car back in (reasonable time period), you're going to have to approach the BBB as well as file in small claims court. You're out $2,200 and all this time, and still don't have a running car.
BTW, how bad was it when it went in for the 1st time vs now? (was it shifting at all when you brought it in, was it doing what it's doing now? worse? not as bad? etc), might lend some credibility to your frustration