I bought an iTunes gift card and after getting the e code, it said card already been redeemed

I bought an iTunes gift card with an online website which is.... Mygiftcardsupply.com and after some minutes, the e code was sent to the email which is used to purchased card and when trying to redeem, it says the card has already been redeemed. i was debited using the PayPal account. I really need support from the iTunes please

[Edited by Moderator]