Follow your company policy. I worked at Burger King, one of my co workers was taking an order from a lady who kept asking how much her total was, and then cancelling food on it and changing her mind. I guess she was trying to keep under a certain dollar amount? Well at the Burger King I worked at, any cancelled food on an order needed a manager's password. So the manager had come by 3 or 4 times at that point. This was during dinnertime, mind you, so there was a line of customers out the door waiting. Finally, my co-worker pulled out a pad of paper and a calculator. He started writing this woman's order down and totaling it out by hand. The woman asked him why he was doing that, and he told her "When you make up your mind about what you want, then I'll put it in the register." This pissed off the lady, so she grabbed the notebook and tried to hit my co worker with it. He snatched it back from her and told her "Get out of here." My manager was only going to write him up for it, the manager agreed that the lady absolutely deserved it, but my manager had to follow company policy.