How to relink Steam account?

My buddy was trying to surprise me by getting back into the game, but the game was unclear about how to link his account when he got the steam version (It at no point tells you to go to Mogstation to use the Steam code). So there's an unfortunate series of events that occurred that needs undone.

Basically, he renewed his sub to see if that got past an error. It didn't work and it wasn't until I pointed out the code and where it was supposed to go that the accounts got linked.
After telling him about the unlinking form he could fill out... So SE ended up unlinking his account after it got properly linked. Now, his sub from the original service account is still active and free month on Steam are two different service accounts!

How do we relink them? Or at the very least, refund the month of sub on the service account he isn't using?

Thank you for posting in the Final Fantasy XIV Technical Forums,

Unfortunately the issue you are describing is something we are not able to assist with in the Technical Support Forum. As your friend is the account holder, we advise for him to contact the North American Support Center.
This thread will be moved to 'Separate Support Required’.

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