how do you cancel itunes card

Hello and welcome to Apple Support Communities, debrahunsaker!

I understand you want to cancel an iTunes Store gift card. I'd be happy to provide information to help you out.

If you've lost your iTunes Store gift card, there's no way to cancel it. Here's a few of the things you can do with it:

Redeem App Store & iTunes Gift Cards and content codes

If I've misunderstood your question, please reply with any additional information you can provide so we may help you out.

Have a great day!