City of Joburg Electricity dept exploiting us

CoJ has been taking us for a ride since June 2015. It started with a bill I received of R17 308, which has now escalated to R22 781. I have no complaints over the other amount, but the electricity billings leave a bad taste in my mouth. No form of intervention have I not explored to try and resolve the matter, incl. going to the Sandton walk-in centre, calling, emailing and in Aug 2015 I lodged a complaint with the office of the Ombudsman. They also promised to get back to me after 90 days and instead there was correspondence from a Mr Ray Moodley at CoJ Customer Relations, who acknowledged receipt of the account query and advised that a customer relations agent from the VIP department will be contacting me with progress on the matter. This was on 27 January 2016, and I haven't heard anything since. I've send Moodley numerous emails, which I received read notifications of, but no response. Did I mention that on 17 January 2016 our prepaid electricity meter was installed? Interestingly, I still receive CoJ invoices billing me exorbitant amounts for electricity despite us paying R300 X 4 weeks=R1200, far less than what they are billing us for. We are being de*****ed here. HELP!!!!