Kotak Mahindra Bank — Regarding money refund

I would be paid overdue charges through kotak mahindra mobile app. but that not reflects in actual numbers in application. that still showed as overdue. after one of the person send QR with the name of kotak mahindra bank and after transaction done on that QR, that will work now application show overdue amount 0. But I paid total 4061 rupees for overdue amount 2030 rupees. now that person not receiving call and nor respond on whatsapp.