Nope, have had the same, single, account since 2006. I buy MS currency two or three times a month from GS and have had zero issues. I splurge on a $20 game code and it all goes to hell...and I can't afford to throw $20 away on nothing.
I feel your pain on money always being tight. Have you checked your Microsoft account balance per chance? I know a while back when I bought codes through Gamestop it has been the cash value for the games..... not the actual games. But it's been a few years since I've bought codes from there though... Also, you should be able to see it on here if by some crazy chance it just needed extra time to process
Edit: You can also try
1.signing into xbox.com
2.Click on gamerpic and select profile
3. Click My games tab
4. It should show every game linked to your XB1, PC, or 360 depending upon selection
5. Hopefully see ME3 and Profit!