Useless contact customer service line

City of Johannesburg contact centre is of no use , I have been trying to call them for almost 3 days, each time I was holding the line for more than 30min with no answer, equally the customer query department is as useless as it comes, I complained about my meters reading which was stuck , after a lot of ups and downs the meter reading was fixed , I emailed my new meter readings but they are still charging me under estimated