Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello, good day and thanks for your question. I understand that you are looking into cancelling a subscription that is not under your name but was paid using your credit card.
For this, if you have access to the account or if you have means of communication with the owner of the Microsoft account then you can follow the below support links from Microsoft including the removal of your card on the account.
As there is an existing subscription, you will need to cancel it first and then you can go to https://account.microsoft.com/services/microsoft365/billing and try it from there or try to turn off the recurring billing at https://go.microsoft.com/fwlink/?linkid=2277073.
https://support.microsoft.com/en-us/accounts-billing/remove-a-microsoft-account-payment-method
In the event that you are unable to follow the cancellation process, you can reach out to the bank and block specific related charges or have them replace your card to avoid any unwanted charge/s in the future.