Tamil Nadu Electricity Board [TNEB] — Late payment details

Hi
Consumer No:[protected]
I forgot to pay my bill last time and my connection has been disconnected.when i approach local EB and they asked me to pay around 12k for a bill amount of 2400, may I know the reason for that and on what basis late fee will be calculated.
Actual reading for the missed one: 29920 on 19/12/2022 and disconnected on 23/02/2023 on that time reading is 30485.

Please let me know for more information call me at [protected]