Sorry about your LBS. Guess they don't want to stay in business, I certainly wouldn't go back.
Agree. Seems like a dumb/cheap thing to take such a stand on. If it were an expensive service that had your bike in their shop to begin with, then I would be especially mad at them for balking at swapping out the tube for you.
If it were my shop, I'd say come on by and I'll hand you another tube and apologize for the trouble.