I bought 9 New iTunes Cards this Morning 3 show they are not valid.

Hi, I bought 9 iTunes Cards this morning, 6 work, 3 say they have been used, I went back to Walgreens and they said there is no way they were used they would not have rung up at the Cash Register, so now I have one $50 iTunes card that shows as used and Two $25 iTunes cards that are not working but the other 6 were all fine, is there some type of time delay on certain iTunes cards or was I sold bad product Walgreens does not take returns on Gift Cards they said I had to go to the iCloud to sort it out, I have receipts and pictures or each activation slip and pictures of the 3 Cards that show as being Used. Please help it adds up to $100 of which I can't afford to loose. Thanks, Randy