I purchase a batch of gift cards and redeem them slowly as needed. I can't tell you why we do it this way but we've just been doing it this way for years now without issues.

We keep gift cards in their originally packaging. They're usually in a clear plastic bag, and then the paper envelope holding the gift card.

I went to redeem 3 of these cards. 2 of them had no issues. The 3rd kept telling me it was already used. I had just opened the plastic bag, taken the card out, and pulled the code cover sticker. I tried using both my phone app to read the code and website manually putting in the numbers/letters

I've been talking to support but they just tell me it's been redeemed. One was asking me who redeemed it (the name of the person), and I told them all possible names who could've redeemed it (all family) and they said none of those people.

Has anyone experienced this before? If so, how was it resolved?

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Edit:

Gift cards were purchased from amazon website. Their default "Amazon.com Gift Card in a Mini Envelope"