Firstly, apologies for any inconvenience this issue may have caused.
Few VM sizes are currently not available in certain region due to demand (this is the case for many free trial accounts VM sizes). The solution is to create your VM resources in neighboring regions during these periods of high demand.
There are few other customers who reported similar issue, and redeploying in another region was successful.
I would recommend you to try deploying VM in US Central, US North Central, US West, and US South Central.
What is Microsoft doing to avoid capacity issues in the future?
Ensuring capacity for our customers is a top priority for Microsoft and we are working around the clock to deliver on this. The increasing demand for Azure services is evidence of the popularity of Azure, and emphasizes the need to scale up our infrastructure even more rapidly. With that in mind, we are expediting expansion and are improving our resource deployment process to respond to this strong customer demand. We have identified several improvements on how we load-balance under a high resource usage situation, and how to trigger the timely deployment of needed resources. Furthermore, we are increasing our capacity significantly – and will continue to plan for strong customer demand across all of our regions.
Hope that helps.