Overcharging a pensioner

My mother of 69 who is a pensioner received a water bill charging her for actual reading of 180 days (R2114.89). We don't have problem with actual vs estimated reading however its not legal to charge a client for 180 days in one invoice. When I queried this with the accounts team they advised that the reason they couldn't get a monthly reading is because when the water meter reading staff came out to her property there was rubble on the meter so they couldn't take a reading which was a lie because I could take pictures of the meter reading . We were then advised to go to Plumstead city of cape town to query the bill, when we explained the bill the lady at the counter was more interested in just making a payment arrangement and not listening and acknowledging the query as to why the water meter readers could not come out on monthly basis to read the water meter. This is not right to charge clients after so many days and still a pensioner with bill of R2114.89 ,60 days is still understandable but 180 days???***..I want this complaint looked into