MakeMyTrip India — Refund not yet received for Madrid to Kolkata flight

I had purchased two return ticket through Makemytrip in Air India flight for my parents in law from Kolkata to Madrid on 15th February 2020 with the return flight on 28th April 2020. They had travelled to Madrid on 15th February but due to COVID-19 caused lockdown, air India cancelled the return ticket from Madrid to Kolkata on 28th April.
PNR: YFKBY
ticket number: 098-[protected] (ASOK KUMAR PANJA)
098-[protected] (SUMITA PANJA)
I had raised a refund request on Makemytrip on 19th August and received a response that my refund application (RA) vide reference number [protected] / [protected] has been raised with the airline and I will get the refund within 45-60 days. However I have not received any refund till now and when I tried to call to Makemytrip customer care, it always gives an automated response only. Please process my refund request as soon as possible.