Dude, the guy's working with company procedure. He offered you a refund, which is all he's got permission to do. What on earth did you expect him to do?
As for your rude e-mail to Gamestop, what's that going to achieve? Someone in a call centre will take one look at it, send you a nice, placating e-mail, and forget about it.
Sometimes stuff doesn't work. Deal with it, and stop talking as if it's everyone's fault but your own. I deal with customers every day, and the worst ones are the people who feel they're entitled to anything more than what consumer law grants them. If you buy something which doesn't work, you can get a refund, or you can storm off.
Sales clerks, general managers, and customer service employees deal with people like you all the time, and being belligerent just means they won't bother helping you. Hell, if I was spoken to in the same manner that you're speaking about those GameStop employees, I'd just tell you to get out of the shop.
We're retail employees. Just because we serve you doesn't mean we like you.