Calcutta Electric Supply Corporation [CESC] — Excess bill in the month of June & September 2020

Address:

S V RD, Birati, 24PGS(N)

I have paid all previous bills but every 3rd month the bill is generated very high.
In the month of June 2020 the bill was Rs. 2440 units consumed: 383
In the month of July 2020 the bill was Rs. 150 units consumed: 25
In the month of August 2020 the bill was Rs. 420 units consumed: 71
But the In the month of September 2020 I have got the bill of Rs. 2610 units consumed: 384.
I have paid all the bills except the month of September. How can it possible the bill is so fluctuated in every 3rd month and there is not mentioned the Previous Meter Reading & Present Meter Reading in the bill.
Please correct the bill to pay the within due date. Kindly take the necessary steps as soon as possible.