Do you not have a copy of your warranty? Should state pretty clearly in there if you can do your own work.
With any repair being done by a shop, it's always a good idea to find out what it's going to cost ahead of time. I always hold them to a quote. Or sometimes I will take them a list of things to do, and say, "Do as much as you can in one hour" They love me.
Anyway, it does sound like a 'bend over this won't hurt a bit' servicing you got today.
Why don't you try putting some cold compresses on your wallet? :p Might make it not hurt so much.