Myntra - Fraud by Myntra

I placed an order online for * Truimph Doreen Burgundy and beige color bras worth Rs **** on Myntra on **th November '**. Myntra fraudulently sent me a cheap black used bra on **th November '**. When I complained about this on **st November and raised request for return and refund of my money, they have been harassing me and are asking me to wait for ** hours everytime I call them. I have raised complaint on twitter as well but no response from them. I have called more than ** times on their help center and I have the call recording where they have said it is their fault but have still not collected the wrong item and not given me refund yet. Myntra has cheated me and is not refunding me my money saying there is some technical issue at their end