Paschimanchal Vidyut Vitran Nigam [Pvvnl] — received bill arrear whereas we have already paid the last bill.

Account no [protected], anand swaroop. This is regarding our electricity bill dated 28.5.2020 period of 4.3.2020-28.5.2020. According to this bill the previous reading was 15545 and new reading is 16615 which is equal total unit of 1170. The total amount of the given unit is 7240rs but in this bill electric department hv added one more amount of previous arrear of 2190.
Before this bill we have received a bill dated on 4.3.2020 period of 5.2.2020 to 4.3.2020.in this bill the previous reading was 15176 and new reading was 15445.. Total unit consumption was 269 and the amount of rs 2073 which was already paid now when the complete payment of earlier bill was paid than how come there is arrear of 2190rs was added in new bill.. Kindly check and advise.