Swiggy - Swiggy cancelled my order without my consent

I placed an order and the order got accepted. After one hour the delivery guy called and told the item is not available. I just wanted to know why the order been accepted in the first place if it was not available.
I chatted with the customer service to get it resolved and asked to refund me double the order amount as they wasted my time without any food delivered to me. I did ask them not to cancel the order until they agree to refund the double the order amount. After some time they cancelled my order without taking my consent and initiated a refund of the order amount.
Now, I am really pissed off. I really want them to refund a hefty amount.
My order no. #***********
The order was made on *th June **:** pm. I have attached the order cancellation mail.