My Wifes key is running into this exact same problem, except that she received her key a few hours after the OB had started. Follow the instructions in the email from best buy. Input the key and owned: "That key has already been used"
We're on the phone with best buy CS currently, But a word from cryptic would be nice.
Question: Why is my Game Key invalid?
Answer: The most common cause for this error message is a mistyped key. Please recheck each character to make sure the Game Key is entered correctly. If you are certain the key has been entered correctly and continue to receive this error message, please log into your account and submit a Billing Support ticket making sure to include all crucial information, including full Game Key and where the key was purchased.
I got an open beta key from best buy prior to the Jan 12th date. When I registered on the site, i entered in the key. Since this is showing in my account, I'm hoping that means once I'm done downloading that everything is ok to log in.
Otherwise, when I tried to enter it in the beta key window it said already in use.
I'm wondering if you already have the files downloaded and tried logging in with your account? Maybe you pre registered like I did and "used" your key for that, so when you actually are ready to play its set up for you?