Spicejet and makemytrip - Refund of Cancelled Flight

We had booked flights to travel from Chennai - Siliguri on **/**/**** and return on **/**/****. But since the flights were cancelled due to the *st lockdown, we were not given a refund and provided a credit shell of the same amount. Later, the DGCA had directed the airlines to refund within * weeks after claiming a refund request. We have done the same but there has been no response neither from the Airline nor from Make My Trip.
We have contacted the customer care of spicejet multiple times and they are unaware of any developments regarding the refunds. They only direct us to travel by **/**/**** failing which the credit shell would expire and we would lose the entire amount.

We are in a fix as to what to do next and how to proceed.