If it doesn't work, try a different account!
I've been getting these cards for years from Amazon for my mom. I've only recently had a problem with it. My mom was trying to redeem the card she got for Christmas. It wouldn't work. Apparently, this happened to her with another card as well, and she was only able to redeem $19 of it instead of the $25. She has multiple accounts, so I had her try it on a different account. For some reason, it wouldn't let her redeem it on one account but it let her redeem it on another account she had. It was the only way she was able to redeem it.
Rating: 4 stars