Hostage negotiations!

Have a Vumatel fiber line in my new residence. The previous tenant has immigrated overseas. So for 3 weeks I have been phoning everyday trying to get access to the line so that I can have internet, but Vumatel won't release the line to my ISP because the previous tenant's ISP, MWEB has not released the line. It is just endless circles of phone calls and emails! How can a company like Vumatel allow other ISPs to hold a fiber line hostage and punish people who have done nothing wrong but just want access to internet??? Surely I can't be the first person who has had this problem! When will Vumatel sort their systems/procedures to protect clients against this???