Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Greetings!
This is Tin, sorry to hear that you're unable to cancel your subscription since you cannot log in to it. I understand how you feel. Regarding this, it will be best to reach the Accounts & Billing Team so they could check the best option to cancel your subscription and address the charges that you had on your account. To do that, Kindly open this link: https://support.microsoft.com/contactus/
Ensure that an active MS Account has been signed in
Type "Chat with an agent" and hit Enter.
Please click the "Contact support"
Please select the "Products and services"
Please follow the prompts to connect with a live agent.
You may also choose the "Call me back" option if you prefer to receive a call.
Once you're connected to the Live Agent, please let them know about your issue so they could check your account and address your concern.
Thank you,
Christine L