Flipkart — Product is not being returned

Address:

Flipkart India Private Limited registered address is Vaishnavi Summit, Ground Floor, 7th Main, 80 Feet Road, 3rd Block, Koramangala Industrial Layout

I have received damaged product, the product is puma sneaker
it is used and stained product I have tried returning the product but the product is not being returned, I have called customer care for this issue for 10 to 12 times they are just saying they will solve the issue but the issue hasn't solved yet. I have purchased this product through their flipkart pay later, the due amount is been increasing day by day