Refusal to Update Details

I keep getting telephone calls at all times of the day (often multiple times in a day) from Telkom asking to speak to my husband. I have informed them umpteen times that they have the wrong contact number on record and have given them the correct number to call (which they have informed me they already have on their system). When asking to remove my number completely from their system (I am not their client and do not wish to receive any more calls), I either get treated with a bad attitude, the phone being slammed down in my ear or sarcastic laughter. The contact persons also never put me through to a Supervisor so that I can take the matter further.

Who can assist to ensure that my name and number gets permanently DELETED off of Telkom's records? If this continues, we will absolutely close all of our accounts with Telkom as their service is rude, not in the interest of their clients and just plain non-existant.