Did you sign up for a trial subscription to Apple Music? If you use Family Sharing, did somebody else sign up? The trial is free but after 3 months it automatically rolls over to a paid subscription.
Manage your Apple Music membership on your iPhone, iPad, iPod touch, Mac, PC, or Apple TV - https://support.apple.com/HT204939 - "Learn how to cancel your membership, change from an Individual to a Family or Student membership type, or join an existing Family Membership.
See your purchase history in the iTunes Store on a Mac or PC - http://support.apple.com/HT204088 - Does not include purchases made by others under Family Sharing; those have to be checked from their accounts.
"Family purchases and payments - https://support.apple.com/HT201079 - "Are you the family organizer? Learn how purchases work with Family Sharing, what you're responsible for, and how to manage family purchases and payments."
If you think there really is something that shouldn't be there:
Report a Problem - http://reportaproblem.apple.com - "Sign In for help with iTunes purchases made in the last 90 days"
Other ways to contact iTunes Store Support:
https://support.apple.com/contact
https://www.apple.com/emea/support/itunes/contact.html