Kotak Mahindra Bank — Charge back request

Hi sir my name is Naveen Kumar Chauhan my kotak bank registered mobile number is [protected], i want to raise a charge back request .

I did transaction of 549rs on 5 may to dhani merchant .
But this transaction become failed i wait for refund for 7 days no one refund receive me.
I complaint in dhani merchant customer care he also say wait for 2 days but no one refund received me at yet . Again i complaint on dhani customer service he say that no on payment receive me on 5 may plz contact your bank for charge back request. He also share a email of charges back request .

I request to kotak mahindra bank for refund my money of 549 rs .