Yatra - Full refund not processed

I have cancelled my international flight ticket booked through yatra.com on *nd April, **** due to covid-** crisis which lead to the cancellation of all the flights to and fro from India. As per the airlines guidelines displayed by yatra, I am eligible for full refund of my ticket fare but yatra has given me only partial refund (which is paid in two installments) that too after a lot of mail queries, remainders. They have never responded to me properly. After a lot of mails for my refund, i was initially given Rs.***** on **st May,****. After that again when I have approached them repeated for full refund, I was paid only Rs.**** on **th June ****. In total the i have to be paid Rs.***** but I was paid only Rs.***** after writing a number of mails. Now yatra is bluntly denying saying that I was paid for my eligible refund. For getting this partial refund itself I had to go through a lot of mental torture and wasted a lot of my time in this due process. If I am eligible for only Rs.***** then why did yatra pay in two installments? The second installment was paid only because I fought for it else, yatra could have never gave me that amount. This is clearly cheating. Why should a customer beg for his rightful refund?