Unable to cancel an order before it is even shipped

I have placed an order with Flipkart to buy a cycle and as the item shipment was delayed and not serving my purpose, I tried to cancel online well before item is even being shipped but no cancellation option was provided. Also called the Flipkart customer care and they couldn’t cancel the order as well and says “Item can not be cancelled”. Being an online e-commerce portal and customers purchase the items just by looking at the fancy photos posted by sellers, what rights do I have to cancel the order and how the consumerforums can help in this regard.

Thanks in advance.