Matrix, sorry, I was making a general rant about guys and their attitude toward FFL's, not you in particular in this situation. If he allowed your pistol to be degraded in condition he did very wrong, but I can't really think of a real solution other than to take it back and "chalk it up." Read some of the other posts, and please accept my post as a general response to some of them, and many others I have seen.
For the record, I have an FFL, but operate only as a "kitchen table" dealer. Please indulge me a little story you may get a kick out of. I shoot with a pistol club. I also have property that I drive 250 miles to each weekend. Between there and home is a distributor. I make several "bullet runs" a year to save my buddies and club members the cost of shipping bullets/powder/primers. I usually pick up $1000+ of stuff each trip. This is a pain for me, but I look at it as a contribution to the club. I do it for NO markup. This is my choice, I realize, of course. Last April a guy gave me $30.00 for two boxes of a certain bullet. His total came to $29.74. I showed up with boxes of bullets, etc. with an adding machine tape on each one so I could keep it all straight. I carried armloads of stuff to each guy, including him. I noticed he kept following me after he already had his stuff. When I stopped back at my truck for another load he comes up behind me and says, "Uh, you owe me .26 cents." I gave him a dollar and said, "keep the change." Mind you, I had made numerous runs for him, and saved him many dollars over the last 9 years that I have had my FFL. Thoughts of numerous incidents like this prompted me to use the term "cheap bastards"--it was not aimed at you in particular. My bad. Sorry! [:)]