Booking fee requested for one extra patron

I had my birthday lunch at this establishment and booked for 19 people because that’s how many people I had invited. One of my friends showed up with the husband and the rude owner told me that I have to pay R500 that would not be added to the bill as a “booking fee” for the addition of one person. Further more she said I had not be honest about my number of people attending. My friend and husband arrived 3 hours after all 18 of us had been seated. This was a horrible experience. The owner is extremely rude, I’ve never been to a resturant in which the booking fee was not added to the bill and how do you demand a booking fee when the patrons are already seated at the establishment! They are a bunch of ****mers and the ****tails suck because they are all premixes. You ruined my birthday party!