PGVCL — Bill paid and still showing pending amount

Address: SHRI PORT OFFICER SAHEB , PORT COLONY , WAGHAWADI ROAD,Block No. A10 , VILLAGE : BHAVNAGAR, TALUKA : BHAVNAGAR, DIST : BHAVNAGAR

During lockdown period, i paid rs. 1636 online through net banking as my bill shown on pgvcl website. After that i received bill of rs. 3172 on date 02/06/2020. As i already paid 1636 on date 24/04/2020, i paid rs[protected] = 1536) through amazon pay on date 11/06/2020. Now i received bill of rs. 3593.99 on date 27/07/2020 in which it is showing that my pending amount 1089 after deducting covid relief of rs. 612.38 which was added in bill i. E. 2504.93 + 1089.06 + 3593.99. As i have already paid amount as below :
1636 paid on date 24/04/2020
1536 paid on date 11/06/2020
3172 total paid in two parts
Now how amount is pending of rs. 1089.06... Please clarify

As i understood i have fully paid amount of rs3172 in two parts, now i should not receive bill showing pending amount.

Hence i have paid only rs 2505 in present bill and not paid pending amount of rs. 1089.

Kindly look into the matter and now i should not receive any pending due bill.