Flipkart Internet Private Limited - Sale promised not completed

My Order ID - OD******************. I had placed a Mi TV order through online platform Flipkart using my Credit card and had paid Rs. **,***. The product was promised under an Rs. **** discount offer if paid through prepaid means. After no update for * days, Flipkart has asked me to cancel the order as they cannot provide any other resolution and has not provided me with compensation for the harassment caused by them. Also, the product is out of stock on their website now. If I purchase a new product from Mi.com or their Mi retail store I will incur a minimum of Rs. **** extra on the product. I have also lost interest income on Rs. **,*** due to my money blocked by Flipkart for more than * days. I was asked by their customer support to cancel the order else the order will remain pending and money will be kept blocked with them. Due to which I had to cancel the order. They have outright denied any compensation for the mental agony caused the additional cost I will have to bear due to cancellation and the interest loss my money is taken by them.