Re: Mechanic messed up car repair. Should I expect a refund?
This is all good advice.
Ask for a refund. If he doesn't give you one (which he probably won't), calmly explain that you'll be telling people to avoid his shop.
It might be a good idea to have a portable recording device with you -- a cameraphone with video is ideal -- just in case the guy gets angry.
"I prefer books and movies where the conflict isn't of the extreme cannibal apocalypse variety I guess." Redsfaithful