Calcutta Electric Supply Corporation [CESC] — high billing despite being out of station

Address:

6 Mandeville Gardens Kolkata 700 01, Kolkata, West Bengal, 700042

To
Senior commercial executive
Cesc
I am out of station from 29/03/2019 till 16/08/2019. Hence i have switched off the main connection of electricity of my home from 29/03/2019. I am not using the meter from 29/03/2019 till 16/08/2019. Inspite of not using the meter now cesc has sent a bill for the month of april 2019 amounting to rs 1180/-. How is cesc raising such a bill at this period when no electricity is being consumed from 29/3/2019? I have already paid rs 900 for the month of march 2019.