Apple Gift Card Didn’t Work

So I got an apple gift card for $25, and when I tried to redeem it, it showed a green circle around the code and it said that I had $27.01 in my account. Then I went out of that and I checked how much money I had, but it said I still had $2.01. When I tried to redo the card, it said it had already been redeemed. What do I do?