The problem is its showing as a new account. I don't think there is anything simple you can do to fix it and you would just have to wait for support to sort it out.
The only way I can see would be to set up a new account at full price but as I cannot guarantee this would work I wouldn't try it.
It may just give the same problem. A domain added to an account which used a promo code cannot then be used on another account.
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