Telkom is ***********. Messed up my billing and Fibre contract

Telkom are NOT deactivating my fibre line withe Vumatel even though my contract has been cancelled in Oct 2019. Unable to connect with my new ISP as the Telkom has NOT deactivated my Fibre line with Vumatel even after numerous calls & requests to do so. Telkom's incompetence and trsdiness is holding me "hostage' and I am having to pay exorbitant fees for data and internet my cellular contract. What will it take for Telkom to deactivate my Fibre line with Vumtel. I am Fustrated and at wits end with them.