Myntra.com — refuse to return/exchange the product

I received the product with the wrong size and not as i expected, however i have collected insider points on myntra by mistake, and informed the customer care immediately to help me out as i wanted the return of the product. However they clearly refused to help me out and refused to make any return or refund.
The behavior was totally wrong as i informed them in a minute about how i accidentally chose the points collection option. I even told them to just exchange the product and i can buy something else with the amount as the product delivered to me was of bad quality. But there was no assistance received from the customer care people. Order was delivered to me on 27th nov 1pm and on the same day at 11 pm i tried to place the return which i was unable to do so.