Amazon India - Refund not processed

I had ordered an anti-static grounding mat on ** January **** from Amazon.in with Order# ***-*******-*******. When the mat came in with a hole and with rusted components. I filed a return request. Since pickup service was not available in my region I was told to send the item through courier myself. I was told to send it preferably by speed post. That's what I did. Now despite following up with customer care on multiple occasions and providing them with the proof of dispatch, my refund has not been processed. Total amount to recovered includes item cost and shipping cost. (Rs.***+Rs.***). If I had the harassment I have undergone due to calling Amazon multiple times, the figure would be much higher. Did not expect this from Amazon, a company where I have to spend tens of thousands in purchases over the last year.