Myntra.com — Order got cancelled by Myntra after date date of delivery passed

I had placed an order# 119049553796564297601 of Dressberry sweater from Myntra. Delivery person did not contacted me and I got status as delivery attempt failed in my orders history of Myntra app. It was not delivered to me till given date of delivery by them after which I contacted Myntra customer support. Two days later they cancelled order mentioning internal issue as reason. Just because I had ordered at a discounted price, my order was cancelled. I feel cheated and when contacted they said that they can do nothing about it! Is this the way customers should be treated? I was very disappointed and angry at the same time. I will take this issue across platforms and even to the court if they do not come up with a proper resolution.