Flipkart — Wrong item has been delivered and return request being rejected by Flipkart

I ordered a Puma White sneakers for 1500 rupees on Flipkart and I was delivered ab entirely different item. A pant has been delivered. The delivery guy clicked delivered on his phone before I come outside of my house and he got the money from me and said me to give return product request on Flipkart app itself. I did what he said and my request has been rejected. I have talked to their customer care people 3 times and now no one is calling me back or helping me with replacement or refund. Extremely disappointed on Flipkart and it's my first worst experience with online purchase in this 6 to 7 years