Hello, thank you for reaching out to Microsoft Q&A.
You can try the account recovery form here to recover your account.
Important: The account recovery form can only be used if two-step verification isn't turned on.
Link to Account Recovery Form: https://account.live.com/acsr
Remember to use a familiar device from which you've frequently accessed your Microsoft account, as well as a familiar location. Microsoft will review your responses and respond within 24 hours. If you are verified, instructions on how to log back into your account will be sent to you, and if you are not verified, you will need to submit the Account Recovery form again. You can do this up to 2 times every 24 hours.
To cancel your Office 365 Subscription, check with your bank to see if there's an option to cancel automatic recurring charges directly from their end. This may be another way to stop the charges.
Alternatively, you can contact Microsoft Accounts and Billing Support directly.
https://support.microsoft.com/en-us/home/contact
Let me know if you still need more help.