Account handed over to VVM after line cancellation

Line cancellation with Telkom in January 2018 and 1 year later account handed over to VVM debt collectors with constant pestering from them - phone call and messages.

I submitted line cancellation on time before I left Kimberley. But Telkom took 2 months to cancel the line, it was told they would back date the cancellation. What's promise was not delivered and my account has been handed over to debt collection company 1 year later.

To avoid constant pestering I decided to pay Telkom and NOT VVM (company who phoned me from no where). But no communication between the 2 companies and no way of contacting Telkom or VVM. And I have paid now for something I did not use for 2 months AND getting pester by VVM.