Xbox Live Code already Activated but not on my Account

See with the support, they will help you.

https://support.xbox.com/

Thank you for reaching out and sorry to know you're having this issue.

I believe Xbox support are able to know at least when the code was redeemed, were you told when the code was redeemed ? If so, was it before or after the day you tried to redeem it?

Thank you, ,

I was told it was activated on the same day.

If you mean that code was redeemed ( activated) on the exact same day when you tried to redeem it and you are 100% sure of that; I should say that the code was redeemed on an account that you may have access to. Or account belong to a family member maybe.

I suggest that you go back to Xbox Support. From my experience, Xbox Support will be able to know which account has your code, but, only if they found that one of your accounts matches the one that has the code. Moreover, they may able to help you, mostly
if the code could not be redeemed, I am not sure about this case scenario though. And of course most retailers dont return used gift-cards, that's why no one could take responsibility if you asked me.

Regards.

Thank you, Salmoro,

I was told it was activated on the same day.

Hi Thanos Opressor,

Had Xbox support contact me on 5 occasions. They are telling me there is nothing they can do.