I'm having similar problems. Entered my NA preorder code on Tuesday, got an EU code in the mail that evening. Figured it was fine since people on numerous forums are reporting that they could reenter their NA code again and get a new 20 digit NA access code. Waited, tried on Wednesday and started getting Error 2, which is that the code has already been used. Waited, did all the profile adjustment stuff, still Error 2.

Went through the live chat support, and was essentially told to wait and see what they do to fix it. It is probably worth it to try to get through to support though, they'll take your preorder code, where you preordered from, and your EU access code down then escalate your ticket. It might not amount to anything, but it might be something you'll end up having to do down the road.