Considering you gave him sort of misleading information (getting mail acces makes account last forever? don't think so) and the fact that you gave him a lower quality product than the one he paid for (he paid for a premium version of the games, and you provided the basic one) I think replacing the account and leaving the amount pending (the 6$) on 0 (he gets a replacement instead of 6$ in credit) is fair.
Please let me know when the account has been replaced.
Thank you. I'll let you know when he sends me the fifa 21 ultimate edition account