Bangalore Water Supply & Sewerage Board [Bwssb] — water bill of july 2019

I have made payment online (Razorpay) for amount of 299/- on 3rd july for rr#e-108240 which was successful. However the amount showed up as arrears in my next bill.
As i was out of station i went ahead with payment with arrears to avoid disconnection.
Now the bank is asking email from merchant (Bwssb) for refunding amount.
Bank and merchant are making me run from pillar to post for this issue resolution.