CESC — regarding excessive bill charge

Sir/madam,
I, Chandrani Banerjee, is a consumer of CESC service. My consumer no.- [protected] and customer id- [protected]. My bill has been charged Rs 820 against consumed unit 60.This is quite absured because last month my consumed unit was 79 and I paid the bill of Rs. 470
I request you to lodge my complaint and see to this matter urgently as the last date of payment is 20th Dec. It is really a harrassment to charge a heavy amount unreasonably.
Thank you,
Yours sincerely,
Chandrani Banerjee