Manager calls customer a ****

So yesterday while myself and friends were at Rosewood Terrace having a nice Sunday lunch. We all placed our orders and when it came they got the one order wrong. It was sent back to which on return the order was still wrong. My friend asked for her burger patty to be well done and got it back twice medium rare. The second time it came back wrong it was first told that it was because of a mix up in the kitchen and that there was more than one burger that was meant to go out. Telling me that they don't track your order correctly. After that my friend asked that the order be taken off the bill as she no longer wanted to wait, but a 3rd burger was brought back to her. She then told them she does not want it. The floor manager then tried to sweet talk his way by trying to give her other options on the menu as well as a free beer. She again said that she doesn't want anything, he asked her to cut the burger open to see if it was right. My friend again said that she did not want it anymore as everyone else had eaten. The manager then said he will remove it from the bill. On receiving the bill, the burger was still on it. We called the waiter to get the manager, to which he then called us ***** and said that he never said that he will remove the burger from the bill. He called the customer a **** in front of 5 other people. I was disgusted in the treatment she received.