Registration issues

Hello,

Today I made an account on the Square Enix site.
When I try to log in to The Lodestone site from ARReborn, I get the following message:
"You could not log in because the service account in question is not registered.
If you would like to log in to the service, please log in to the Square Enix Account Management System and register the service account."

The first time I went to Account Management and tried to register the game by entering the code that came with the game, I used small letters. I got a message that the code was wrong and I tried again with capital letters. This time I got a message saying that "The entered code has already been registered."

When I try to enter the game with the FFXIVLauncher, it get the same message as before: "You could not log in because the service account in question is not registered.
If you would like to log in to the service, please log in to the Square Enix Account Management System and register the service account."

So what can I do when I can´t register the game. It keeps saying the entered code has already been registered. Please help.

Edit: The account that I´m using now I made a couple of days ago with my second e-mail adress to try out the free trial. I wanted to use my main e-mail with the account that I'm paying for. That's why I have two accounts right now. Also with the account for the Free Trial I have no problems. I can play the game just fine. I have these issues with my main account.