Maybe worth reading this and contacting CircusMidget_TS:
http://forums.ubi.com/eve/forums/a/tpc/ ... 3451018878
CircusMidget_TS wrote:If you login with the Ubi.com account you used the key with then it should take you right into the game. If you login with the wrong account or with a new account, you'll be prompted for the key and if you try to enter it in, you'll get an error saying the key has already been used.
Just be sure that you're logging in with the account you first entered the key with. If you're not sure which one you used, send me a PM and I'll assist you further.