Inability to register my game

So I've been gone all weekend and came back to FFxiv asking me to register and set up a subscription, which is fine and all, but I cannot seem to do so. I already have an account and when I give it the one 20-digit code to register my game, I am informed that my game is already registered. I followed the instructions of the previous email from the 22 August back when I first got the game and redeemed the code on the website. I would really like to play my game, what am I doing wrong here?