How to investigate a billing charge from Microsoft

If you don’t recognize a charge on your account, go to the Manage your payments page of your Microsoft account dashboard and select “Investigate”. Learn more. Here are the most likely causes for an unrecognized charge: A Microsoft subscription has recurring billing enabled. Someone you know, such as a family member, bought something with your card.

https://support.microsoft.com/en-us/accounts-billing/how-to-investigate-a-billing-charge-from-microsoft