Telkom Complaint

I cancelled my landline and ADSL on the 3/3/2017. Telkom terminated my landline and then continued to bill us for Softcap. I eventually managed to get that cancelled in October 2018. They were to reverse all charges to date plus the interest. Till today we still receive a monthly account. We have been handed over to 3 different debt collectors. Not sure what else to do. At our wits end. Don't have a problem paying for a service we use but to be billed for one we haven't used is outrageous.