When organizations use Azure IaaS they are themselves responsible for management of the operating system and all the software running on top of that. Microsoft is responsible for management of the virtualization layer and anything below that layer (IT infrastructure). So, when things look broken or organizations have an issue with the components Microsoft is responsible for, you need to contact Microsoft support.

You do need a support contract to be able to get support. Contracts are available in various forms. Microsoft Support can be contacted over the phone or by submitting a support request.