Myntra.com — Missing item in packet

I had placed an order on Myntra, Order ID# 1204566 [protected]. There was supposed to be 2 products in the packet but I received just 1. I did not receive 1 Levis blue jeans worth Rs.2, 558 which I have already paid for.
I raised complaint on myntra support but they declined my claim saying they have checked their process and have delivered the product, which is a lie since I did not receive it.
As soon as I received it, I called the delivery agent for the missing product but he did not respond.
Order date: 16 May
Invoice was present for both products in the packet, but there was just 1 item