Office 365 - Forgotten Password

Well what a complete shambles this experience has been.

Microsoft’s customer service is a complete and utter joke. 

I have a client who runs office 365 and has forgotten her password and upon trying to get it reset, we have no idea who the alternative email or phone number belongs to. I have submitted numerous recovery forms with proof of last sent emails and everyone of them keeps getting denied.

The business relies on their emails and they have no been without emails for over a week and I personally have spent 2+ hours per day on the phone with Microsoft and and I just keep getting panned off to the next person (I counted 8 different people on one phone call) and eventually the phone hangs up.

anyone any idea as to how to go about this?

Thanks