How do I unredeem a voucher from a nonexistent account?

My dad emailed an iTunes gift card to my IPhone 6S but I accidentally left out a letter in my email address so he sent it to the wrong account. Unfortunately the money has still been taken from his account and I created an email with the same name as the one I accidentally sent my dad and I signed in and redeemed the code thinking it would go to my email address, but then I discovered that I could have forwarded the email to my account, so I did that but it said the gift code had already been redeemed. So I woul like to know how it can be deactivated and sent to my actual account.