Yatra.com - International flight return ticket cancelled but refund is not given

I booked a partially refundable international flight ticket ( for my wife ) from New Delhi to New York (USA) and back to Delhi from yatra.com of Rs. *****.
The return flight was much delayed by more than * hrs due to which I cancelled it with airlines Air India. As per the airline policy, there would be no cancellation charges by the airline due to delayed flight by more than * hrs and they several times confirmed it through its customer care. But when I demanded the applicable refund from Yatra.com over customer care, they denied it saying that cancellation charges are more than the claimed refund which is not actually possible at all.
As per the yatra cancellation charges of the partially refundable ticket is Rs. **** through customer care and Rs. **** through online cancellation. Though online cancellation and refund claim on yatra.com is not active. So continuously I am demanding my refund which is approx (*****- **** = Rs ***** approx) for the return flight.
Yatra.com as a travel agent cannot alter the flight charges after the cancellation of the ticket. The day when I booked the ticket through yatra.com, the split Air India flight charges from Delhi to New York was ***** and New York to Delhi was Rs ***** approx

-I demand my applicable refund of my return ticket.
- I demand transparency in split fares of the combined ticket.
I request you to do the needful. Applicable documents are attached to this.