Hi! My name is Aj and Im an Independent Advisor here to help! Im sorry to hear about your account. In order to cancel the subscription you have to recover the access of your account first. https://support.microsoft.com/account-billing/i-can-t-sign-in-to-my-microsoft-account-475c9b5c-8c25-49f1-9c2d-c64b7072e735
Please submit an account recovery form at https://account.live.com/acsr. The information you will give should match the information in the system so give as much detail as possible like old passwords, devices, purchase history, account usage, etc. You can submit up to 2 forms a day. After submission allow 24-72 hours for verification. Please check this guide on how to properly submit the form. https://support.microsoft.com/account-billing/help-with-the-microsoft-account-recovery-form-b19c02d1-a782-dee6-93c3-dc8113b20c42
If the form keeps failing please contact support directly at https://support.microsoft.com/contactus using a working email and choose Account / Security / Recovery then pick support agent or chat.