Telkom is the worst!

Telkom is the worst telecommunications company. I cancelled my contract in June with them. got a call to confirm the cancellation and then in receive an invoice saying I owe them. The cancellation mysteriously vanished from the system and I am told to pay for an ADSL service I haven't used since June because I took on fibre. Every month I get invoices with reconnections and all sorts of things. apparently they can't close the contract because I owe them form July. I am certainly not paying for a service I did not use!!!