MakeMyTrip India — Passenger was Covid infected but full refund amount not processed

I had a booking from Hyderabad to Dibrugarh on 12th Jan 2022. The booking id is NF7UMDM4TBIXLP1U1756. My wife was Covid effected and so I had to cancel the booking one day before the travel date. I had submitted the RTPCR certificate to the airline as well. But I didn't get a full refund.
The booking amount was Rs. 11084 and the refund amount was only Rs. 3125