its Christmas and i got wow with all expansions everything was going well made my account added wow and burning crusade but when i enter the authentication key it says.

An error has occurred.

The authentication key you entered cannot be claimed. Please check the key and try again. Alternatively, you can enter this key for a different region by changing the leading part of the www.battle.net URL (ex. “eu.battle.net”) in your web browser, or for a different Battle.net account.

i have entered they key carefully 7 times on 2 different pc's help i wana make my damn goblin!!!!!!!!