Calcutta Electric Supply Corporation [CESC] — Excess payment of bill, consumer I'd: [protected]

On 21.12.2020 I paid my October 2020 electricity bill through credit card. The bill amount was Rs 590/-, but due to some technical problem my bill was paid twice. Instead of Rs.590/- I paid Rs. 1180/-. I was having an idea that the excess amount is adjusted in the next month bill, but I found that in November 2020 bill my earlier excess payment was not adjusted. Please do the needful.
Regards,