Myntra - Fake Nike product delivered by myntra

I purchased a Nike tessen shoes from myntra. First of all, they sent used shoes with broken box. Then I exchanged the product. After using shoes for * to * days I feel some pain in my foot while wearing Nike shoes. The shoes original price is **** rupees and I got the product in the sale at **** rupees. I checked the reviews about these shoes from other sites and each and every site mentioned that this shoe is very comfortable as also written in shoes "Engineered for all-day everyday comfort". But the shoes I bought from myntra is not comfortable at all. Myntra has no ratings and comments section so that any person who already purchased the product can give their opinion. I raised the issue to Nike India as Nike provide * months warranty for their shoes but I got return message that if the discount on shoes is above **% then they don't provide a warranty. So then I contacted to myntra and they said that we cannot return used products. This is not the first time while I faced issues from myntra. Each and every time when I purchased shoes myntra I faced the issue. Are they really provide original products? My friend recently purchased Reebok shoes worth **** rupees and she said to me my *** rupees is more comfortable than this. Then she returned the shoes to myntra. I want my money back. Please help me.