Myntra - Refund not issued

I ordered a tshirt worth *** on **th february ****. The order was received on **th february ****. I didn't like the fit so i placed a return request the next day itself. From that day on I was getting return will be picked up today message on daily basis but never got a call from pick up agent. But after every * days the status gets updated as pick up failed. And on *rd March **** I got a message telling from Delhivery courier service that the return will be picked up today and received a call on same day. I gave my product to the pickup agent and after that i recieved a message from ecom express that my Amazon return pick is successful. I was confused because I didn't have any Amazon orders or return. I thought it maybe a mistake and didn't care about that. Later I didn't get any refund and the status of my order was "delivered". So i reached out to myntra customer service and told them about the incident. They said they didn't receive the product so no refund. I was following up for so many days and they didn't even care to take the responsibility and kept saying they didn't receive the product. As a customer I did my part but myntra isn't worried about that. They didn't investigate properly