Incorrect readings

In July 2015 we received the municipal bill with no readings with an amount of R2500 for 73days. Obviously we were shocked as we had always received a bill with reading and had been paying per reading previously. We did not know where the 73 days came from or the amount of R2500 as our normal bill came between R1500 to R1800. Upon query this amount at the City of Johannesburg branch in Midrand we were told that this was based on actual and the next bill will be lower. Not totally convinced we settled the account. In August to our amazement the bill came to a whopping R6424.00 this for 101 days! Why would we be billed the previous month 73days and the following month 101days? We went once again to the City of Jhb only to be assisted by an *********** person who would not listen to our side of the story and insisted that the bill was correct and that the meter reading was correct. Furthermore we were informed that new meters were installed. How is it possible to be billed for so many days in two consecutive months and why did our bill spike from an average of R1500 to R2500 and then R6424.00? Why is there no one in council that answer our questions or assist us. PLEASE HELP!!!!