Myntra.com — I paid the money but Myntra did not deliver my product

I paid the money to Myntra for two products as per cash on delivery as it had the invoice of two products!! After the payment when I opened my parcel, there was only one product inside the other was missing!! I immediately raised an enquiry on their help centre!! They committed to solve my issue within three days!! It has been more than a week since they committed, no reply no revert is there from Myntra’s side!! Neither they are giving me any refund nor giving any written reply!! When i raise a call back request, they give a missed call for a second just to put the status of cancelled call in the record!! My hard earned money is looted by Myntra!!