Q: how come i dint use my debit card but it keep on charging my charges???

This is a user-to-user forum. There's no way for us to know why you were charged. If it's a recurring subscription, you can go to Settings > iTunes & App Store, tap your Apple ID > Manage, and see if there are subscriptions to be cancelled. If it's not a subscription, contact Apple Support.

iTunes Store charges on credit and debit card statements - Apple Support