Flipkart - Issue with Replacement of Phone

I am a defence officer, I had recently ordered and iPhone ** from Flipkart, They sent me the phone but it was scratched on the bezels, after that I tried to get a replacement but they didn’t acknowledge it at all, then after almost ** calls I got a replacement request raised, but they said to wait for *-* days and after waiting they told that the seller(NGVIR Retails New Delhi) has rejected the replacement, I again called them *-* times now they say to wait for another * days and my replacement period will end in * days, I have been financially and mentally harassed during the process, I don’t have much time and even after being exhausted after coming back from work I keep calling them to get this replacement done, but nothing is getting acknowledged.