Mahadiscom faulty electric meter - (consumer no-172054771695) and huge bill

My name is nitin sharma, I lived in a rented house in thergaon and from nov 2010 to till date our meter has been faulty. My consumer no. Is 695. The billing unit is 4636/Sangvi sdn/Ph no 550. From the last nov 2010 to till date they are sending us default bill of 138 units every month. We always pay on time. But this month we got the bill of 70/- Inr. When I go to check why this huge bill comes. They told me that your meter is faulty that's why they made some average. I told them, I agree with that please provide me the complete detail, how do u calculate such a huge amount. But they are not ready to give me the details.Please take quick action on the same as we are incurring loss each month. Quick action will be appreciated.