MSEB — Excess bill for the month of june 2020

We have received huge bill of rs7670.00 for the month of june. During lockdown i have paid the bills given by mseb through my credit card company twice and by me once through google pay.
Exactl rs.3500 is paid by to the mseb during last three bills.
Even though they have given us a huge amount of bill to me.
Kindly help.