OVERBILLED AT ETHEKWINI FOR WATER

My water bill has been increasing in amount for months, when inquired at the Billing Department, they have no comment, Why are different house holds paying different rates charges??? Why are the areas charged different prices??? Why is the kl always the same, whereas my neighbour uses the same kl and pays far less, what is going on .. Why are we charged differently but use the same water litres.. Who is rigging the system, no one can respond to my emails @ eservices