Calcutta Electric Supply Corporation [CESC] — Excessively high bill

Sir, I'm a customer of CESC for several years but never faced such a situation before. We have two meters in our residence, one of which is with Customer ID - [protected] . This particular bill is showing excessively high amount (₹1190) that usual for the month May 2021 having a due date of payment 29/06/2021. We generally pay ₹150 to ₹300 for this particular billing ID. Even the payment of last month was rs- 180. But this time we got a due bill of ₹1190. Which seems to be a mistake.
I'm writing to get a help about this High amount of bill correction. I'm sure there must have some mistake.
We will be highly obliged if you kindly able to help us about the getting of a correct amount of bill to pay off .
Thanking you
Prabir Das
O/166 Dewan Bagan Lane, Kol -24
Cust ID - [protected]
Bill Id - [protected]/05215