Airindia — AirIndia Refund

I had booked International ticket from Hyderabad to JFK via Delhi and same for return. I had to cancel return journey (JFK - Hyd via delhi) as AirIndia had rescheduled flight from Hyderabad to Delhi and rescheduling caused wait time at delhi of 7hrs 30 minutes.
As per Airindia policy, I am supposed to full refund (Due to reschedule of flights by Airindia) for my remianing journey.
I had cancelled tickets on April 14th 2021. I have called 7+ times airindia customer and sent 6 emails to Airindia for refund. But, still my refund is not processed.

E-Ticket No:[protected] and[protected]

1) Name of passengers : Sheenu Jindal and Etash goyal ( Total 2 passengers)

2) Schedule of travel

Hyderabad to JFK:
02 Mar 2021 : Hyderabad to JFK via Delhi

JFK to Hyderabad (Return Journey)
21st Apr 2021: JFK to Hyderabad via Delhi

Regards,
Sheenu Jindal
M: +91 [protected]/[protected]