Flipkart — Cancellation request initiated without confirming the refund amount

Hi,
I booked a ticket from Chennai to Colombo for 09 Nov 21 (Indigo) and back for 12 Nov 21 (Srilankan Airlines) through flipkart travel with Booking ID FF[protected] for an amount Rs 17401. On a day prior to my DOJ ie., 08 Nov 21, i contacted flipkart customer care to know how much i would be refunded if i happen to cancel my travel tickets. They told me that i would get the information through the website.
After logging-in in my flipkart account, i tried to check the refund amount for the onward leg (Chennai to Colombo) and had to follow two steps:- first page i clicked "Proceed to Cancellation" and then on second page "Calculate refund". On the other hand, while checking refund for the return journey (Colombo to Chennai) which was Sri Lankan Airlines, after clicking on "Proceed to Cancellation" on the first page, it directly put the request for cancellation. The second page with an option of "Calculate refund" did not appear instead it directed me to the page displaying my flight details with the status "Pending Cancellation" for Colombo to Chennai flight.
I contacted customer care immediately to tell them about this technical glitch but they were not ready to listen. I requested them to retrieve my cancellation through the airline, that was also denied saying it cannot be done from their (flipkart) end and it is upto airline to cancel it or not. After that also, i asked them how much will be the refund if the ticket is cancelled, they told that they are not aware and i will get to know within 90 days and the refund will be processed 9 days after that. They couldnt help me any further so i was told that technical team will be calling me within 24-48 hrs but till 18 Nov 2300hrs no call was made to address this issue.
Since there ws no response from the Flipkart side for 10 days, customer care was contacted again and same replies were given as last time. I was again told that a call will come from the technical team within 24-48 hrs.
I got an email on 19 Nov 21 that the refund amount is only Rs 3502.

The total cost of the ticket from Colombo to Chennai was Rs 11, 225. But due to technical glitch the flight was automatically cancelled with only Rs 3502 as refund.