Unable to access Global Admin, username not recognised, need tenant recovery billing active

Unable to access Global Admin account for Microsoft 365 tenant. Username not recognised and I need tenant recovery. Billing is still active.

I am the billing owner of a Microsoft 365 Business subscription for yutoriacupuncture.com.au but I have lost access to all Global Admin accounts.

The original admin account email is returning “username may be incorrect”.

No other admin or business emails are recognised. I have a business email associated with the admin account i can still log into. 

I recently briefly cancelled and reinstated my domain which may have affected tenant linkage. I also recently joined a university Microsoft 365 organisation which may be affecting sign-in routing?

I have tried login.microsoftonline.com, admin.microsoft.com, password resets, and incognito browsers with no success. I have tried contacting support via phone and email but keeps cutting out, saying it can't identity me, or sends me into a loop hole with the support chat bot. 

I need Microsoft to escalate this to tenant recovery or Data Protection team to restore Global Admin access using billing and domain ownership verification.