Snapdeal - Substandard quality product and Refusal to honor warranty claims

I had bought this product on **th september **** (invoice attached), and it was delivered on **th september. On **nd December, this product (an office chair) broke abruptly when someone was sitting on it, badly injuring the person. The person's weight is ** kg, so it cannot be said that the chair was overloaded. On writing to snapdeal (the company) regarding the product failure and warranty through multiple fora, they flatly refused to entertain any warranty claims (This product has a * year warranty as per their website), saying that physical damage is not covered under warranty. My complaint against the company is on two fronts: *. Supplying of sub standard quality products *. Refusal to honor warranty Please help.