Indraprastha Gas Limited [IGL] — Wrong bill and threatening for png disconnection

We were not in our apartment since December 2019 till September 2021.
Before locking the apartment our meter reading was 275.000, and we clear all dues till meter reading 275.000.
During period of locking of apartment, IGL has taken the advance payment from us on 26/03/2020 and 11/06/2021 for INR 552.64 and INR 781.21 (attached payment history snapshot from my IGL account (PaymentHistory.JPG).). These payments are done on estimated bills raised by IGL as the apartment was locked and no actual readings were available. Total of these payments were INR 552.64 + INR 781.21 = INR 1, 333.85.
Our apartment is unlocked in September 2021 and the actual reading is available now which is 320.000.
We are requesting IGL to provide us the bill from meter reading 275.000 (last meter reading upto which payment done) to current meter reading 320.000. And also adjust the advance payment of INR 1333.85 in the new bill.
IGL is harassing and threatening us for disconnection of the gas line but not providing correct bill with adjustments. It is also affecting us adversely without any fault from our side. Can you please help us to get the correct bill from IGL with advance adjustments.

From
VINEET TYAGI
BUSINESS PARTNER NO. [protected]
METER NUMBER 15790907