Telkom internet cancellation inadequacy

We have been trying to cancel our wifi with Telkom (using Vumatel) as the fibre provider for 6 months now. Finally on the Telkom system it shows the contract cancelled but the line with Vumatel hasn’t been freed up, so Telkom internet is still running but we cannot get our internet service provider (who would provide a better service than Telkom) to connect as Telkom hasn’t freed the line. After more than 15 calls and reference numbers from Telkom, the problem still hasn’t been solved and I’m at a loss as to how to fix this problem. Vumatel will only deal with Telkom and Telkom don’t know how to help. Never use Telkom as the service is bad and the staff are not able to problem solve.