Flipkart - Defective Product Delivered

Flipkart delivered a product which is completely defective. When contacted them they say it's not returnable. But they are providing defective product and they accepted that it's defective. They have an open box policy but we cannot check the product if it's working. The open box is just to check if it's damaged. So this is Flipkart and their vendors are providing defective products and doing fraud with customers to earn money out of it.