Do you mind me asking what you ended up doing at Gamestop that worked? I'm in that same boat now.
Oh, so sorry to hear that! How much do you still have? I hope you don't have the $1000 in GS gc's that I had! I was considering taking about a 15% hit by either selling the cards thru Raise(or the like), or Ebay, or selling the cards to Ebaycardcash where I would have gotten $858 for $1000 in eBay egift cards(they were giving like $85.80 per $100 GS card). That seemed easiest at the time and about what I figured I'd get if I sold the cards and paid the fees they charge for selling.
Then, the poster Jkalai posted some very timely info! Timing couldn't have been more perfect, this all wouldn't have worked with on another week. He had earlier in the week suggested I could buy GS games and then do
trade-ins, but I wasn't sure how that would work at all and seemed like a lot of work. But then, that Sunday he posted info on games they had for a great sale, like $17.49 - maybe $26, most pre-owned at GS. That was like less than half normal price, I saw those titles the next week at like $49.99 and $52.99! The key is that it happened to coincide with a deal
Best Buy had that week of buying trade-ins of certain titles at $25. He shared the BB link to the titles of the games that would work. So I used my GS gc's to buy the titles at GS, most were pre-owned, though a couple new titles also had sale prices of about $20 - $25. I also used a GS power up rewards card that gave a 10% extra off, and then traded in and got BB gc's. So, between buying some games at $17.49 and more at the $20 - $25 sale price, I basically came out just over even, not losing a penny! I bought 3 titles of various games per Playstation 4 and Xbox. BB only allows three trade-ins of each title per game console, per year, per person, and they definitely keep track! Somehow it worked out with me trading in, along with my DD26 and her DF, and we got it all done. It all took a week, used 3 different GS's that were pretty close. Had to finish in that week as the timing of the sales and the BB deal was only that week. I just couldn't believe the great luck I had as any other timing and it never would have worked out so well for me.
It's still something that could work if you could watch GS prices and find what trade-ins might work. Maybe they do other things like this at other times, I don't really know. Good luck, I hope you get your GS cards converted somehow!