Makemytrip - Refund not received after flight got cancelled

I had booked a flight for *st April **** in the month of January **** through MakeMyTrip. Unfortunately, the tickets were cancelled by Jet Airways and I was supposed to receive a refund for the cancelled flight.
I tried calling MakeMyTrip multiple times and also email them but each time they had only one answer: "We are following up and in constant touch with Jet Airways to get updates on your booking refunds and will keep you duly informed about the status of your refund. We will process the refund as soon as we receive it from the airline." It's been more than * months and I'm still waiting for my refund. Here are my details:
Booking ID: NF**************
JET AIRWAYS *W-***
BOM - CJB
Invoice Details
Invoice No. : ****************
Invoice Date: ****-**-**
GSTIN No. : **AADCM****R*ZZ