Make my trip - Request for Refund from MakeMyTrip for the flight cancelled by GoAir on August

I booked a go-Air Flight(GO AIR G*-***) from Chennai to Mumbai for **th August ****(**:**-**:** am) through MakeMyTrip App.
Booking ID: NF**************
PNR: V**EYF
TOTAL PAID: INR ****
Traveller: BHUPENDRA SINGH NAYAL

Please see the attachment for detailed proof of the same. 

But this flight got cancelled by the Go-Air Airlines, So I had to book another flight.

Now when I try to Request a Refund in Make My Trip I get a message :
“Your Refund Request Could Not be Processed” (We couldn’t raise your refund request because as per the airline, your Chennai-Mumbai flight is still operational.

I tried calling the GoAir helpline but the Call went unanswered