Flipkart — Flipkart giving offer which they can't fulfill

There was offer ongoing 10% discount on kotak mahindra bank debit and credit card but i didn't get any discount before placing order i did ask customer care about this and he told me to place order cashback will be credited after that but after placing order now Flipkart customer executive are saying that discount offer are given by bank so contact them.i did purchase my product from your site not from any bank.I did contact my bank and they are not helping either got scammed by Flipkart.
I have all the toc screenshots.
Order ID - OD[protected]