Flipkart - Mobile not delivered

I order a mobile(micromax infinity n**) in flipkart they delivered me a dead mobile, later i raised a return request then after one day technicians from flipkart came and check the mobile and approved return request. after that delivery boy came with new mobile but refused the take the dead mobile as its display is not getting ON and he left without replacing the mobile.I raised concern regarding the whole issue to the flipkart they told me to wait till */**/**** but i dint get any resolution.Later they called me on **th and asked me to wait for ** hours and later they prolong the date to **/**/****. Every time there are prolonging the date but they are not giving any resolution to me.I got psychologically depressed due this issue because i planed to give this mobile to my mother on special occasion and i lost my patience to.