Unauthorized payment
I had an unauthorized payment of $15 taken out of my account for iTunes but I didn’t make any purchases in the last few months.
Question marked as
If you've looked at the purchase histories of all iTunes accounts you have linked to the card and not found it (and checked iCloud storage) : See your purchase history in the App Store or iTunes Store - Apple Support
and if it's not : About payment card authorization holds from the App Store or iTunes Store - Apple Support
contact the card issuer