MakeMyTrip India — Non refund of convenience fee when flight was cancelled by airline

I booked an Indigo flight ticket in Makemytrip for travel from Kolkata to Dibrugarh on 14th January 2022 (Makemytrip Booking ID NF26S7MYSAS2RYNM0472). Indigo canceled many flights on their own because of the 3rd wave of COVID. My flight was among them. Since Indigo cancelled, I initimated MMT and asked for refund of the amount 6708 that I had paid.

However, MMT refunded only 6108 deducting the convenience fee. Now I understand convenience fee deduction when the flight was canceled by me, but when airlines cancel the flight, how is it my fault? why should I pay a convenience fee? This is an unjust policy and unfair trade practices.
I want to bring Government of India's notice to such unfair trade practices and urge MMT to refund the full amount paid by me including convenience fee