The thing with Game Stop is you have to continue to spam the process.I do. Missed every last one. Gamestop wouldn't check out for me
Once you click add to cart and you get the "please wait, adding more..." refresh your browser.
Click add to cart or pre-order again.
Repeat the process until you get a captcha.
Once you got the captcha whatever step you're stuck on continue that step until it goes through or you get banned.
Game Stop banned me last time for having 9 browsers open doing this process with 6 tabs a piece.
They removed my ban and I got two bundles.
I've yet to have an issue with Game Stop not allowing me to return parts of their bundle.
What form of payment are you trying to use?