Zomato — No refund after order cancellation

I cancelled the order within 5 minutes of ordering it. I talked to the restaurant and they were fine with cancelling the order since it was not prepared yet.
However, zomato charged the entire amount of the order as cancellation fee and did not refund it even after multiple requests. They forced me to surrender into their fraudulent and faulty company guidelines/rules to cancel the order and get zero refund. I did not want to waste food and so had to cancel. Who charges the entire amount as cancellation fee even though the food was not prepared ?