Mahanagar Gas — inappropriate billing amount

I have received a debit note from mahanagar gas on 14.09.2018.

In this note they have mentioned that the earlier meter was not functioning properly, so on basis of their new consumption pattern they have calculated 1.146 scm / day which results into outstanding amount of rs. 27, 760.

Till now i have paid all my bills regulary. But no idea, on what basis they have calculated 1.146 scm / day.

If the meter was faulty then why they havent changed the meter in 2014.
Why they have taken such a long period to resolve their fault.

Due to their negligence we have facing this issue. The mistake is from their side not from ours.

We have contacted mahanagar gas, regarding the same but they have ignored to resolve my issue. And they are forcing for the bill payment

Ca :[protected]