Flipkart - Unethical business by Flipkart

From Flipkart I bought * TVs with an additional buyback guarantee policy in the last * years. As per the policy terms buyback discount can be claimed while placing the new TV order. Few months back I found that this discount showed up on the product page but disappeared soon after I navigated to the payment page. Upon notifying it to Flipkart it was reported as an internal problem on the Flipkart side and the same problem perhaps affected some other customers. Due to no fix available on it, Flipkart customer support suggested that I go with regular exchange and then after delivery buyback and normal exchange difference will be credited back to my bank account. Now when I was about to place an order during the Republic day sale, I contacted Flipkart to confirm once again about the suggested approach. This time they simply changed their stance and denied by stating account credit was a miscommunication and refund will be made in the form of a Flipkart wallet credit. Wallet credit will be valid for a year and one must have to redeem it only in Flipkart whereas buyback policy terms states that the discount should be applied up front for an eligible purchase without such condition. Anyway, when I placed an order and shared the order details with them to confirm the difference credit post delivery, they avoided confirming in writing. Since I experienced that they kept changing their statement even after a written communication, I couldn't take the chance of accepting the delivery without a confirmation fearing to lose my TV with normal exchange price. Again after numerous phone calls and emails when Flipkart failed to acknowledge the credit option, ultimately I had to cancel the delivery. Long story short, by now I understand that Flipkart kind of cheated me by paying *-**K to buy additional policies that they are not going to honor at all. I thought of using the policy to upgrade the TVs from time to time but my plan failed to work. Moreover, so many hours spent on the phone, writing emails to Flipkart customer support also caused unnecessary harassment throughout the process. Being such a reputed brand, I am surprised to see how fearless they are to violate the policy terms and thus cheating a customer.