Ajio Reliance Trend - Refund not made after Pick up the product

I had purchased Puma shoes from AJIO site for Rs.****/- on */**/**** but due to a fitting issue I raised a request for return and refund immediately after getting the shoes as per your return policy. Got a message from you for pick up and the pickup agent picked the product back on **/**/**** after checking it completely. Then got a message that your refund is initiated and you will get your refund soon but after following up many times didn't receive the refund. Suddenly one day I received a box from AJIO and after opening it was found that there were cheap ***/- Rs. shoes in the box (attached images for your reference) and got a message from AJIO that we received a non AJIO product from you and we have sent back this to you. How is it possible?

Firstly I didn't request for a replacement and demanded a refund then why they had sent me some cheap shoes against my refund. Secondly it clearly reflects that their pick up agent or store employee picked the original shoes from me and changed the product , what is my fault in that? Now they are denying to refund my money.

After picking up the product it is the responsibility of the company to ensure refund the amount but they are committing fraud and why should I bear the loss of Rs.****/- for their mistake.

I have talked to your customer care executive and he agreed that the return products are always taken back after checking it, then why I am responsible for this. Now their staff is saying that nothing can be done in this case and we have closed the request.
This is a very shameful act of such a big brand and nobody can expect this kind of reply. This is the reason people believe in other online brands. they can't cheat the customer like this.
Complaint id is -COM***********