Ajio — Ajio saying its non ajio product while returning

I had returned the product and after verify courier person picked up the product. I have been contacting ajio for refund but they are saying they have received non ajio product so they won't refund and reshipped the non ajio product. I had returned the ajio product and if they received non ajio they they should penalized courier because courier person picked the Ajio product from me. If it was non ajio then he wouldn't have picked up. Please help me to get refund