Myntra - Product delivered but of a different size and not being returnef

I had ordered puma badminton shoes size UK ** and the product was delivered to me on August **.on checking the product it came out to be of a * yr old kids shoe. When I asked for return myntra representative came to pick up the item but informed that since price tag is not their on the product we have to write to customer care and then they will again come and pick up the item. But now even after repeated calls and submissions myntra has still not come out openly with the problem of not taking the product back or returning the money. They had raised a request that their supervisor will call me up within ** hrs but even after a week there is no response from myntra. I feel I m cheated and myntra is purposefully not responding to the complaint.