Throttle Cleaner Left in Throttle

I just took my car to the dealership for a routine car maintenence. When I drove out of the parking lot and went to turn onto the street and give the car some gas the engine seized up, all my interior dashboard lights turned on and then it just died. I took it back to them and it took them two days to figure out the problem. They had not drained the throttle body cleaner out of the throttle. They flushed it they said and made sure all the cleaner was out, but the car is now driving funny. It is very jerky and not right when I give the car gas. Is my engine okay? Are there long term effects from this? I do not trust them to take it back to them, but I want to know what the heck is going on? Thank you