I tried to change my order and according to the help section I had to cancel the order and resubmit it. I tried to cancel the order less than 5 minutes after I made it and the message was that the restaurant had ALREADY prepared it. Minutes later I got a message from the restaurant that they were preparing my order. So obviously the order wasn't ready when I originally tried to cancel it. I was told that if I tried to cancel it at that point I I would be charged for the entire order.. obviously the helpline was lying when they told me that the order was already prepared