This is why I latched onto my favorite LBS once I found it. Unless they really have to do work on my bike, they'll generally help me out for free. I once had a brake cable get freyed and they gave me a new cable and housing free. At the same time, I once stripped a chainring bolt on a sunday and my favorite LBS was closed...I went to another shop expecting to get a spare for free, instead they charged me $3. Hopefully the bike shop you went to isn't like the latter of those two.