Urgent: Sole Global Administrator Locked Out Due to MFA – Need Data Protection/Tenant Recovery Contact

I have an urgent access issue with my Microsoft 365 administrator account.

I lost access to my old mobile device, on which the Microsoft Authenticator app was configured. As a result:

• I can no longer complete MFA.
• I cannot access the administrator mailbox.
• I am locked out of the Microsoft 365 Admin Center and Microsoft Entra Admin Center for our tenant.
• I am the sole Global Administrator, so there is no other administrator who can reset my authentication methods.

I still know the account password. The only issue preventing access is the existing MFA registration.

I already have an active Microsoft 365 support case, which has been escalated to the Data Protection team. However, all communication is currently going:

Me → Microsoft 365 Support Engineer → Data Protection → Microsoft 365 Support Engineer → Me

This back-and-forth has now been ongoing for more than a week, and we still have no administrative access to our tenant.

I do not want to open another support case.

Is there an email address, support link, telephone number, or other method of contacting the Microsoft Data Protection/Tenant Recovery team directly regarding an existing case?

Alternatively, is there a way to have the existing case escalated so that a member of the Data Protection/Tenant Recovery team contacts me directly?

I simply need Microsoft to verify our ownership of the tenant and reset/remove the existing MFA authentication methods for the sole Global Administrator account so that Microsoft Authenticator can be registered on a new mobile device.

I am available to provide any required verification of our organisation, domain, tenant ownership, billing information, or other information Microsoft requires.