Incorrect billing...

I am renting a property from rapid rentals. The first 4 months my water account was R400-500 per month this month is a R1900 and the photo that i have sent in 17 june of my meter its shows that from then till now 3 aug, i only used 80 unit for almost 3 months. When i call them they. She said she will sent me statements from the munisaplity.. Every month i called them the see if my reading corrosponse with theres and it did. This is seriuosly unexceptable and this must be sorted