I bought 2 $50.00 apple gift cards for my boys and when they went to redeem them it said code already redeemed

I just purchased 2 $50.00 apple gift cards for my boys to use, my receipt shows “activated” for both cards but when they went to redeem them it says code already redeemed??? These cards were not redeemed and I had just purchased them so not sure what it isn’t working. I purchased them at target and even tried contacting them but they couldn’t help me and said to contact Apple for help. I’m so frustrated since I paid $100 on gift cards for my kids and they can’t use them.