Threatened by waiter

Appalling behaviour experienced by my whole family, to firstly experience pathetic service by waiter, threatened us on how his tip should be and within what range because he felt that by providing a takeaway container and bringing our order he felt he was within right he throughout the time told us how and the way we can order and watched that we did not even ask to speak with the manager who in turn did not even approach us to find out if everything was ok and he watched that we walk straight out. Appalled that my family had to be treated like that. I want head office dealing with this as with a threat such as that. I would like to take it much higher.