Why not open a new account? Surely for Azure you don't need a unique phone number for each one of them, right? You could run multiple companies after all. (I've got 5 independent AWS accounts, so expect some sanity like that)
It's more the hassle of it already being attached to my email/devices/phone. Honestly, I'll likely have to do this regardless before this gets resolved.
More hassle than being blocked from spending thousands, hanging on multiple calls, debugging support APIs, chasing docs, repeatedly posting feedback, posting for help in HN? Sorry, but this doesn't compute.
You don't need to change your phone to get a new account. And you don't have to change your personal email. And definitely don't need to change the physical device.
By going through that entire process, I now have a very compelling argument to go to the client with to recommend we switch vendors entirely.
Which will not only ultimately lose Microsoft a significant chunk of money, but will save ME future problems when their systems blow up again and I'm once again unable to get an answer better than, "create a new account and start over" once we're well in to the development lifecycle.
This feature was around well before gmail was a conceived. It was documented in RFC 5233 (admittedly an informational rfc) and many vendors support it.