Delhi Jal Board — inflated bill since last 3 months

Address:

M Block, Saket, M91, New Delhi, Delhi, 110017

My k no. Is [protected]
My bill for dec 18 to march 19 as per
132 kl of consumption
Sewerage charges (It is added to my bill every month but the amount varies each time,) = 2112.84
Meter rent: 48
Sub total: 6835
Adjustment (What is this?)=658
Total bill amount: 7044

It was for 4 months so we paid it.

Again this month we recieved an amout of 12707

8th march to 9may 19
Consumtion: 111
Which is hardly three months where we were not at residence for 10 days.
Consumption amuont is =2915
Sewerage charges= 1749
Service charge= 605
Meter rent=41.33
Total=5310
Adjustment: 352
Total shows as 12707???
Is this a totalling mistake?