Hillary, I would experiment with a couple other bike mechanics.
Maybe your present wrench is on the up-and-up, but hmmm... Wouldn't hurt to see what else is around.
Get the book "Anybody's Bike Book". Get the new version from 1998(?) See my thread on book recommendations in the bike mechanics forum here on bikeforums.com for details.
With that book and a fist full of tools, you can fix almost anything on your bike or at least you will know if you are being fleeced.