Snapdeal nor supplying product neither refunding my money

I had ordered Lenovo tab to snapdeal why their website. I received a product thru courier. I paid its COD amount 10999/- . Tab worked ok initially but it stopped working on second day itself. when contacted snapdeal they arranged for return of tab thru same courier and returned product. I also got mail from snapdeal saying that they are arranging to send a new replacement of same tab. But, i did not get my product . On my number of followups on phone and thru mail i received only a reply " your product is despatched and in transit" One fine day i got a mail from snapdeal expressing their inability to deliver my product , so they are refunding my amount. I was not happy i demanded my replacement and denied refund. But for which they did not respond. I kept regular follow up thru mail. but No Response from snapdeal customer service team or any other body of snapdeal till date. I sent various reminders asking them to reply, but no response from snapdeal. Now i am worried about this situation besisdes mental torture i lost lot of time following up on this also now Till date i did not get product nor refund. Snapdeal had Diwali Offers - and must have done this to many other consumers like me who fall into this nasty trap of online Mega Offers! Kindly advice ! Thanks and Best Regards.