I had tried to sign up on the gift redemption page originally, but it would only return to the redemption page, without providing an error/success message.
I typed in my e-mail and password to log in, and it went to the splash page, giving the impression that I had logged in, when I had not. This had happened from one of the account creation pages, I haven't been able to reliably reproduce it.
So, I was under the impression that I had created an account.
Those aren't the bug, however. That's just bad web design.
The bug is that, I was able to redeem my gift code to my e-mail, which had no account associated with it. I got an e-mail saying that I had redeemed it to an account associated with my e-mail. I went to log in, and only then did I finally get an error that there was no account associated with my e-mail.
So, I tried, successfully this time, to create an account with the same e-mail. There is no game in my profile and I have no way to download or play it.
It's a pretty annoying bug considering it's been several days since I tried this, and I have yet to hear from customer support.
Browser: Mozilla Firefox, V43.0.2
OS: Windows 7