Wait, let me see if I understand this:
Kobo's website glitched and your first gift card was sent while saying that the transaction didn't complete. Without checking your email/account/etc. to see if it went through anyway, you repeated the process. Thus you ended up with two gift cards.
Now, you could have just told your mom "Hey, mom, Kobo borked the transaction and sent your gift card email twice -- only the first one is real, just delete the second one." This would have solved the whole problem. But instead, you wanted Kobo to give you a free $50. When Kobo wouldn't give you a free $50, you came here whining about "bad" customer service (they would only give you what you paid for, or give you a refund, but not give you the gift card plus a refund) ... and bragging that you "stuck it to them" by choosing the most expensive freebie you could find.
I'm not even going to bother writing what I think of the whole thing, because I think you can figure out from the tone of my post what it would be ... and I really don't want to get banned from MobileRead. I'll even let you figure out what word should go after "greedy..."