I would rather gnaw my own leg off than go into a GW store for longer than I need to, and after years of bad experiences I know better than to ask any of the overeager salespeople there for advice or opinions.
That said, every single time I've called GW customer service (and I;ve done it lots) I've come away satisfied and pleased.
I urge anyone who;s got absolutely anything wrong with a model or kit to call up GW and politely talk it out. Within minutes they'll have you sorted out and made whole.
Just some of the things I've called on:
Missing berzerker sprue in a chaos battleforce: got a whole squad of zerks sent to me to make up for it
Missing radar dish on a whirlwind sprue: Got a whole new whirlwind upgrade sprue sent to me
Complained about the old pewter/plastic crusader kit having many, many, many moulding defects that made it very difficult (but not impossible) to assemble: Got a whole new crusader kit hand-picked and personally inspected by the head north american customer service.
Complained that GW store workers sold me a basalisk claiming it had all the chimera bits included (it was the old kit and they were not): Got sent a chimera free of charge for my trouble.
All of it no-hassle, no questions asked (In the case of the whirlie and crusader they asked for the batch numbers off the boxes so they could see if there was a problem with that production run, but when I didn;t have the whirlie box anymore they said it wasn't a problem)
GW's customer service hotline is awesome. No matter what I say about their policies, their stores, their prices, etc, I'll never complain about their customer service hotline