I've also got two GM horror stories (sorry for the hijack)
1) I had the Appleton store install a set of Trijicon night sights on my USP45. They didn't screw up the frame, but they bunged up the rear sight pretty good. Their response: "Too bad, maybe you shouldn't have had us install inferior quality aftermarket parts".
2) I just picked up a few Stag lowers from Eagle in CO. Gander in Brookfield had the cheapest transfer going ($25 to receive all 3). When they came in, they didn't want to do the transfer, because "Gander Mountian doesn't traffic in these types of guns".
I forced the issue, and they grudgingly did the paperwork, but they were not happy about doing a transfer on 3 AR-15's. Seems GM must consider them "non-sporting" or something. Either way, I was planning on dropping another coupla hundred right then (I have other stuff to buy), but decided I'd rather deal with someone else's attitude.
Bottom line after my recent (Monday) experience with Gander: They want nothing to do with our "evil black rifles".
-FMD