Zomato — I don't want to pay my cancellation charge.

Address:

Utpal Dutta Sarani,Santinagar, Barasat,, 700127

I have ordered from Wow Momo this evening through Zomato. Actually I haven't checked my payment option and I have placed my order. But within few seconds I realised that I have placed my order in Cash On Delivery option. So i cancelled the order within a minute. And they are saying that I have to pay the full charge of my previous order. I mean why? I don't think the restaurant starts preparing my order instantly when they receive request? They have their offline customers to serve. I don't want to pay my cancellation charge. Kindly look in to this matter.