Authenticator Invalid Serial code

Purchased two authenticators and can't attach either of them to any accounts.
Both say they have an invalid serial codes and we just got them in the mail today.
Any ideas as to why they can't be attached to accounts? Tried deleting cookies and using a different browser. Followed the instructions as well.
They are the token authenticators.

Thanks

ETA: We are currently in the UK, I know the Authenticators can be used anywhere but is it possible for us to call the Blizzard EU branch to get help even though we use the US version?
We spend a lot of time in both the US and UK, but calling to the US for us right now is very expensive.