Telkom lets us down again

I cancelled my telephone line with the required 30 days notice after a month they tell me I still have to pay they cannot cancel as another provider had rights to the ADSL. After sending all they proof Telkom charges me another month I pay but I am fighting it. Notice in June 2019 for end of July. Ended up paying July and August. Then I said no more. I sent proof of all communication between myself and them and today I got told I have been handed over for default payment.