Zipker Online Services — they send product not as mentioned on their website

I ordered short white kurti from zipker.com. They mention in product details kurti in rayon fabric but when i received my order it is pure cotton. Immediately i request to return and refund but they are not responding properly. It is more than 25 days passed i complain about product but no result. Kurti is price of 1300 rs but with discount it is of rs 1273. And i called on help line number but it is always either busy or no one answer the call. My complain id on zipker customers care is 143583 and it is shown as under process from last 25 days.