Flipkart — Received a complete different product

I ordered a Nike running shoes from Flipkart on 02/01/2023 and recieved the package on 04/01/2023. The item which I got in the package was completely different from what I ordered it was Asics shoes with an Asics shoes box. As soon as I opened the package and got to know that I have received different product, I tried to stop delivery boy and even said that to him that I got a different product but he said he can't take the package back again and i have to raise a return request. So, I raised a replacement request at the very moment and they said to resolve the request issue by 07/01/2023. I sent the photos for the proof but after 3 days they extend the resolution date by one more day and on 08/01/2023 they said your request cannot be accepted. So I again raise a request and this time for refund, they said to wait till 11/02/2023 and after sending all the proofs I didn't get any reply from their side. And on 11/02/2023 they rejected my refund request saying "We’d like to let you know that your return request could not be fulfilled by the seller as their courier partner has confirmed delivery of the item in your order with order id OD[protected] with the product being intact" and after even sending them the proof they are not accepting the request. I have been a Flipkart member for more than 2 years and have always trusted Flipkart till now. But the way they have been treating their costumers is very shameful, it's not only about money but as a costumer who trust Flipkart you have let down your name. I haven't even record the opening of package even once because of the trust but this time you guys have break that trust and it backfired me. I don't know whose mistake is in my case but atleast don't just lie to coverup your mistake atleast try to find where the mistake took place. On what basis do you trust seller or delivery partner as he is saying he had sent the correct product, I have been your trusted costumer for more than 2 years and you are just simply closing my return request without even investigating a bit. Just disappointed completely with the way they are treating their trusted costumers.