myntra fake credit card discount offer

Myntra app claimed an instance discount of 10% on hdfc credit card and I placed a order through HDFC credit card and I had also taken a screenshot of the ad which was showing instance discount of 10% and after placing the order I didn’t get the discount so I raised complain to myntra and myntra support replied saying there was no offer on the date I placed the order. I sent them the screenshot which was a evidence for having the discount, after which they accepted that it would be a technical issue to show that offer but the offer had ended up one day prior. This was totally a lame and easiest way to escape from not giving the discount. Completely disappointed with myntra on this as this has happened for the 2nd time with me.