Farud by Snapdeal.com

I bought an iphone 4s from Snapdeal.com.
After using it for just a day i found it was defective. So i took it to Apple service center. There they told that the phone is a replacement phone and has no warranty. I even called up the apple customer care, they too told me the same thing and suggested me to ask for a refund. So i lodged a complain on Snapdeal customer care on 30th September 2013. Still i havn’t received any proper response from them other than a mail asking for a picture of the phone. This response was given 4days after the complain was lodged, and countless times calling the customer care.
Since then i haven’t received any response from them, in-spite of calling them regularly.
Sir i think they don’t intend to replace the phone or give me my money back. So i request you to suggest me all possible actions that i can take against snapdeal, and guide me through.