registration problem: try again later and we need additional information to verify your indentity

I need to create new business account for new company with organisation e-mail for power bi.

I used link

https://app.powerbi.com/singleSignOn?ru=https%3A%2F%2Fapp.powerbi.com%2F%3FnoSignUpCheck%3D1
in private mode.

I received numerus times error "try again later. Our service in big demand" or something like that at different registration stages.

In the end, the site stopped to propose to send confirmation text to phone number and I received error "sorry, we need additional information to confirm your identity. Please contact our support".

Looks like there are black list for phone number used too many time for confirmation.

Error message has link to support site 

https://support.microsoft.com/contactus?siteid=32ECF580-B446-44E5-8B4D-25F0AFE07779&scope=S&query=Support%20phone%20number

But there are only useless information without means to contact support.

So what to do? I don't have stockpile of phone numbers.