Telkom harassment on pensioners

We have cancelled ADSL line in December 2020 and until today the account has been paid in full and we closed our side of the account. Since then we have been harassed by Telkom which handed the paid up account to Nudwbt in which handed this same paid account to VVM Attorneys. After various calls, emails and telecommunication to all of them they are still harassing my parents who ate penioners and living only on sassa pension. Need assistance in getting them all to read the last emails and start getting this issuesorted for the final time.