EaseMyTrip com - Partial refund of cancelled tickets

I booked a flight for my son for **th April from Atlanta to Delhi through AI. Booking ID is EMT********. Flight got cancelled due to covid and as per govt. instructions the full refund was to be made.
When we approached AI they gave us all the details saying that they made full redund to Easemytrip on *th May and gave us the ARN no. also of the full refund. Esaemytrip never made the refund to us in all those months and when we reached to them in September they made only partial refund citing that the airlines had deducted the money.
It is pure cheating as on the other ticket made through the same airlines but through Makemytrip we got the full refund but Easemytrip has made only partial refund giving the excuse that airlines has deducted it. I reached out to your helpdesk and on hearing my complaint they promised that full refund will be made soon but it has been more than * months but no action has come from them. Easemytrip had been our preferred partner for the last * years but this experience has shaken the confidence and now all the new bookings are being made through other partners if this issue is not resolved soon.