Ajio app - AJIO sent us wrong product and not giving the refund now

I ordered a Sketchers shoes size UK** from AJIO for Rs.****. we filed a complaint regarding issues with size and they asked me to return it and they will give refund. I gave the sketchers shoes to their pickup guy but then they said they received non Ajio product. They reshipped the product back to us and when we received it it’s non branded leather shoes size * . I told them the same they asked me for pictures *-* times and still doing nothing. Their supervisor named sahil told me that they got my product from some other customer and they found issue in shipping but still they are not giving me my money back, It’s been * months now I have been calling everyday and they cook new story every time and ask me to wait for another week.
Every time I call they creates the new complaint and never resolved my original issue. I am very fed up calling them again n again even when they promise me to call back. It’s really frustrating for me as I have been struggling for over * months now.