Consumer Redressal

We got our Cauvery water connection in August 2013. Despite repeated requests to BWSSB we never received a bill from them all this time, Finally,last month we messaged them RR number details etc. requesting them again to generate a bill. WE received a bill this month,for a period of 20 months.The bill amount is Rs.158000(one lakh fifty eight thousand rupees)for a period of 20 months for a consumption of 42 lakh litres of water.THis works out to an average consumption of 7000 litres of water perday. When we raised the issue with BWWSSB, they agreed that there is no way we could have used so much water as they have not even supplied so much water. They said the metre shows this reading which could be because of passing of air.Although they agree that the amount and quantity is ridiculous, we still have to pay the bill.They say,weshould have installed the metre correctly so as not to let air pass through.I don't want to pay this bill as I feel I should file a Consumer complaint re. this