Cannot set up new reservation despite quota having room - and Microsoft has gone silent after acknowledging issue (!)

Question

We are in a very difficult position and urgently need to get our issue resolved, but it's been 8 days and Microsoft isn't even responding to us now.

What is happening is that we have a subscription that has different quotas for different system reservations.

We urgently need to provision a new virtual machine, but get a non-specific message that there is an issue building the machine due to some kind of quota limit being reached. But when we check our quota limits, we have 4x as many available spots as what we are trying to provision. For example, we have 14 processor spots and are only trying to reserve 4.

This ticket was opened as a critical priority on May 11, Microsoft called us from a number from a different company (+91 Mindtree) at 11:30 pm EST so we did not answer thinking it was a scam... so they downgraded the priority and have basically been ignoring our subsequent requests for updates / resolution.

Can anyone suggest how to get this resolved immediately? We have pretty much run out of time and if Microsoft can't help us with the provisioning of servers, maybe we need to move to AWS or similar.