Plastic in my beef burger

My wife and i with 2 very close friends went out for supper. i ordered the beef burger special by the time the food arrived it was cold. politely i asked the waiter to please warm the food and he brought back a new burger. after my second bite i cut through a piece of plastic inside my burger patty. i called the waiter, he looked at it and said he's had it with the kitchen staff and couldn't deal with it.he turned around and said he's getting the manager. from a distance i could see her reaction and body language that she's not interested in coming to our table to firstly apologise for what had happened then hopefully offer to replace the meal! she just told him to sort it out and get me another burger. the waiter returned very upset removed my plate and said he'll replace it.<br> after hours or chatting with my friends we eventually realised we were the only people left in the restaurant and they were busy closing. so we paid the bill and left. i stopped at the reception counter and asked who the manager was she turned around and said i am. i asked if she was aware of my problem she said yes she told my waiter to give me one on the house. but i paid for it!