I took my car to mechanic to carry out engine tune ups in the morning. He changed spark plugs, wires, air filter and carry out the tune ups. After the work is performed on my way home the car was jerking. Automatic transmission was shifting the gear unnecessary. I want to stop at red light but it is not stopping. Engine RPMs at stop in drive gear is very high like 2000RPM. Some how I managed to bring my car home. I started in park gear, put a little gas and take the foot off from gas even then it behaves like I am putting the gas and RPM goes up. What could be the problem? Incorrect tune up performed?

Thanks for your help guys.

What do you drive?
The year, make, model and engine option.
The tech may have accidentally done something that is affecting how your car runs.
You probably should have turned around and gone back to the shop.