Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
1
Log into any Microsoft account you may have on this link.
https://account.microsoft.com/services/
Do you find the subscription listed on any Microsoft account?
If so, select the subscription and click 'Manage'.
From there, you can cancel the subscription and also disable the recurring billing on the subscription.
You may then be entitled to a pro-rata refund, you can check your eligibility to a refund using the steps on this link.
2
If you are unable to locate the subscription on your accounts, using any Microsoft account you may have, try using the steps they provide on this link to find out what that payment is for.