♦ Amazon's anti-fraud process locks cards and accounts if they suspect their terms are broken, the most common reason is being outside of your country and/or using a VPN, but there are others like: reselling/dropshipping, adding a gift card on a brand new account with no other payment methods added, adding excessive amount of high denomination gift cards in a short time period, and others.
How to Redeem
1- After receiving the Amazon gift card code, you'll need to sign in to an Amazon account.
2- Click "Apply a gift card to your account".
3- Next, you will need to enter the Amazon gift card code and click "Apply to your balance".