MFA reset needed - lost phone and access to account with it

Hi!

I am a single-tenant MS 365 account (business) and I lost my phone and cannot access my account any more. I cannot log into my account (because I need my Authenticator) and I cannot set up the Authenticator (because I need to log into my account for that) and I am desperate for a solution as this is my business account and has everything I need to keep my business going.

I lost access on March 2, had access to Outlook on my browser until early morning on March 4 when I completely lost access to everything.

What I do have:

• the phone number that is attached to this account (it is supposed to be one of the sign on methods, but the system won't let me use it)
• the password (also not able to use it to log in)
• the email domain is also mine, I can prove ownership
• I have the last invoice for the account subscription and can also provide the billing information as well as the card number that is attached to this account for automatic billing
• I am still using the same main device (laptop) that I have been using since the account was set up
• I am the only employee and the legally authorized representative for the company that the account is for (and the company name is on the invoice as well as the tenant name)

You can also see that there have been no successful logins since I lost access where the account was used almost every day since it was set up (including some weekends), also proving that I am the user for the account.

I am currently using my old Microsoft account to contact Support via chat but they are telling me a different thing each time we talk, I have literally submitted tickets/contacted 5 different departments/systems and just keep being ping-ponged around and the Support number that I found is asking for an 8-digit code which I guess is also the Authenticator code that I cannot get as I lost access to my old Authenticator so now I have no idea how to proceed.

Tickets that I can track:

• SIR22967120 - I just received a notification that this has been closed because this was not the correct place to raise this
• YQN2RK7D - no response yet
• SGBQ7U9T - no response yet
• 4766105c-db53-40b3-92b8-ddd8c7968a0d - only the auto-reply that request was received an 1 email saying that the provided email address was not found in their system, I followed up with additional details in several emails but no further response or confirmation that anything has been received.
• I also sent an email to 

  mailto:email address removed for privacy reasonsbut no response there as well

I am ready to send any information/documentation to prove that the account is mine, please let me know how to proceed.

I am really desperate for a solution here - this is my business account and everything I need is there - my email with all my contacts, the pending deliverables to clients, my working files, etc. This is week 3 already and I haven't had anyone ask me for any proof of ownership, documentation or anything, I don't know what to do to understand if anyone is even investigating anything regarding this, please help.

Looking forward to any suggestions!