Myntra - Package not delivered

I have ordered Reebok men black tread fast walking shoe. They start their end of season sale in December. I have ordered the shoes in their offer period so to get my product in less amount as general price. I have ordered the shoe on **rd December and paid for it ****rs. They gave me a date of maximum *th January to be delivered. I was tracking regularly. On **st December they updated the courier tracking. After that the never update. I was hoping to get my shoe on the last day they have given. But nothing happened. At last I approached them. Then after some argument, they promised me to delivered my product in * days. And after that, again they repeated the same thing. No update, no messages... Nothing. At last I called then on ** the January, they told me to refund my money back and told that we have provided you some kind of coupon, which I found later that the coupon is something other thing which not same as they told. They told to order a new shoe. But the shoe is not in their stock and the price also get increased. U told that provide me the same shoe in the same price in which I have ordered earlier. They told we cannot do anything, you have to place new shoe and pay whatever the price showing now. I want help in this matter.