Online clothing - Damage product

I had recently purchased a *piece churidar set - which they claim to be vijithra silk. On recieving the product, it was damaged - the embroidery was falling off and the cloth had black marking here and there. Also, the quality of the material was too poor, unlike what they claim to be off quality vijithra silk material. Informed them of the damage and returned the product. They refuse to refund the amount saying it is not in their policies, which i was not informed earlier. They keep on insisting to replace with another piece, which on knowing the quality if the material , i donot want another product.