Is it legal for Flipkart sellers to just cancel orders any time they like?

I had pre booked a wildcraft backpack on Flipkart, which was supposed to reach today. The product tracking showed that the item had reached the nearest flipkart hub.

But then I suddenly recieve a notification late into the night that the order has been cancelled.

When contacting the customer service (both chat and on call), they keep repeating that the “order has been cancelled by the seller for some unforeseen reasons and they can do nothing about it.” Only solution being to place a fresh
order.

Isn’t this gross irresponsibly from Flipkart’s side.
And if in case they can do so, will this not be misconduct towards customers?