Shocking Service

I tried to apply for a VoIP line in August 2019 and was eventually told its only available on a business account. (This is after getting through to agents who have no idea what it is or that it exists.) I phone again beginning of November and was told that they would escalate. I finally get called 2 days later. After a few emails the paperwork to transfer to a business account was signed and sent back. It is now nearly 2 months later and it is still sitting with the backoffice. What must I do to get this resolved? I simple change of ownership??