Myntra.com — Delivered used product and now denying for a refund/return/exchange

I ordered sunglasses from myntra which had no price tags, no serial number, and a defective packaging. Even after chatting with them, calling them multiple times, they didn't provide me with a refund or a return or an exchange for the used product that they delivered to me. Instead of helping me they created false complaints on their portal that I had used the product.

Previously also they had delivered wrong product to me and refused for the return. I had then ordered Bata sandals and what they delivered to me was muddy, used slippers which were not even from Bata.

The brand sucks for the customer support which is in namesake only.