Inaccurate billing,poor handling of queries and no response

on the 25th of January 2018 I topped up my ismrt metering account with R300.00 and I already had R115 remaining which means I had a total of R415 positive balance, to my surprise I received an sms on the 31 Jan 2018 confirming that I have a negative balance of R216.00 and I understand that water and sanitation is billed on the last day of the month but I couldn't understand why I was left with a minus in my account. Then on the 01 Feb 2018 I called the company and I spoke to lady in the call centre who refused to understand my query or go an extra mile to check if the billing was inaccurate, all she said was the bill was correct without giving me a proper explanation, because I was not satisfied with the explanation I sent an email on the 01 of Feb putting my query in perspective and asking for someone to give me a proper explanation and how the calculation was done without being referred to the online portal and I did not receive feedback and I sent a follow-up email on the 02 Feb asking for assistance and no one assisted me or rep**** to my request. then On saturday Morning I received an sms confirming that I have a negative balance of R11-00 not R216 anymore and I got more confused, on the 05 Feb I called again in the morning and I spoke to Dineo Lebae who works in the call centre and she could not explain why I'm on a negative balance or why am I receiving sms' with different amounts and she confirmed that it happens a lot of time and she addressed it with her managers and she also did not understand how the water and Sanitation is calculated she then placed me on hold then she spoke to someone from billing accounts then she later came back and told me that the guy from billing was shocked at how my billing was extremely different from the previous months and he will look into it and call me back yesterday before close of business day and she reassured me more than once that my query would have been sorted out yesterday and I have not received any form of communication till now and I even called about 10 minutes ago to ask her to call me back and that has not happened. I'm so frustrated as I somehow sense that there are some inaccuracies in the billing system and it's nearing the 7th and I wont make any payment till this is resolved and chances are my electricity and water will be disconnected while the query is not resolved.