Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Check if a subscription could be associated with some other Microsoft account of yours. Each outlook.om or hotmail.com e-mail address is a "potential" Microsoft account as well. Try each of them at https://account.microsoft.com/services and, with a bit of luck, you will find the correct one. Turn off recurring billing and cancel the subscription immediately.
If it turns out that you do need further support from Microsoft, see https://support.microsoft.com/en-us/account-billing/how-to-investigate-a-billing-charge-from-microsoft-398c5328-364c-d5e4-ea8f-f5ad60562a93 . Chat support can be accessed via https://support.microsoft.com/contactus.