Impossible to login my business account

Hi everyone,

here is what happened to my account:

1. last year I created a One Drive business account, for that I had to create a Microsoft email: mailto:email address removed for privacy reasons
2. I activated 2FA with my phone number A
3. In December, I sold my phone and forgot the 2FA as I was still able to access my OneDrive (Remember me option)
4. Now when the 2FA prompt happened, I realised I didn't have the 2FA but also forgot my OneDrive password as I never use this specific email
5. Meanwhile I aksed Microsoft support from my personal email, to disconnect my 2FA from my business account, which they apparently did but then told me, when I realised I still could not log in, I should raise the request from the business account, except I can't access it

Now I am stuck as I can't access this account online. I can't

1. recover my password (https://account.live.com/password/reset), message "We don't recognise this one"
2. update 2FA, as I need the password
3. call them as Microsoft contact number never finds an available agent, spent 4 hours waiting last week...

Would you have an idea to help me? I simply need to access my documents...