Myntra - No concession for sending wrong product

I ordered a red tape sweatshirt , wrong product was delivered i asked for exchange they didn't exchange it. My coupons and myntra cash got wasted. It was there fault why should i pay for it.
If they are sending wrong product why my money is getting wasted.
Also they do not respond to the calls and try to blame customer only for their mistake. I've been trying to call them since a week, all they do is to irritate the customer by telling us to wait for their response and not finding solution and when at last i got call from the senior he clearly stated he won't give any concession for their mistake. It is the customer who is fooled and getting irritated. Stop using such fraud sites. If they can't handle their responsibility they should stop working.