Incorrect billing

The bill always comes with a very high amount which is unusual for a township rate, we complained the last time and they only fix it for a month then the same thing happens again. The account was R 0.00 and in a space of a moth it goes to R 2 600.00. They charge us R 2 300.00 for water only in a space of a month, how can they calculate that because no one comes to read the water meter. What can we do because this keeps on? happening.