Eskom

We have been paying Eskom thousands of rands a year for a unit we hardly use, so we sent an inquiry asking what it would cost us to keep the unit, if we turned the mains off (ie. don't use it at all) -that was 2 weeks ago, we have not had the courtesy of a response, so we sent the inquiry again a week later and still, we are being ignored, so we escalated the query to a complaint to their *** - what customer service? we still have had no response from them, now we are wondering if they have been overcharging us and so don't want to respond, or is it just really just incompetence and bad customer service?