Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Please note that this is a user-to-user support forum, and I’m not a Microsoft Support representative. I don’t have access to Microsoft’s internal systems to check or manage your support request or reset MFA. I can only provide information and troubleshooting guidance based on publicly available resources.
Since you have already contacted Microsoft Support by phone but have not received a Service Request/Case Reference number or confirmation email, you can consider directly submitting a support request as a helpful workaround:
-Create a temporary Microsoft 365 tenant using a trial license: Go to Microsoft 365 Business Plans and Pricing and click Try for free to set up a temporary Microsoft 365 tenant with a trial license.
-Use this new account to sign in to the Microsoft 365 Admin Center and submit a support request on behalf of the affected tenant.
-Select the Help & support (headset) icon >If Support Assistant is enabled, turn it off >Type contact support in the search box >Select Contact support, then choose Phone or Email to submit your request.
When contacting Support, please explain that you are the Global Administrator of the affected Microsoft 365 tenant, but you have lost access to Microsoft Authenticator and are therefore unable to complete MFA.
Note: This method doesn't require you to use your new account for your business. Instead, it allows you to create a temporary global administrator account so you can submit a support request, as your original global administrator account is locked out due to issues with multi-factor authentication. The trial account is free for one month. Be sure to delete it after submitting your support request to avoid any automatic renewals or charges from Microsoft.
For further instructions, you can refer to the following Microsoft guides:
Get support - Microsoft 365 admin | Microsoft Learn.
Cancel your Microsoft business subscription in the Microsoft 365 admin center | Microsoft Learn
I hope this gives you another way to reach the appropriate support team.