How to end m365 subscription without admin login

3 weeks ago, my team including admin was logged out because of a business domain update. I lost my MFA device and was unable to sign in again. I called support 3 weeks ago, created a ticket (Case number 2503170040016641), sent another email to describe my issue, and they told me I would hear back from them within 8 hours, heard back nothing. I called again a week after my first call, told me I will be contacted by an engineer soon, still nothing.... It has been 3 WEEKS since my team lost access to the entire m365 service, got 0 help. I'm frustrated and very disappointed. Already switched to Google Workspace. Now I just want to end the subscription since I'm still getting billed every month, but I can't cancel it without logging in. please help