Set For Wish in Arnhem

I used to be the most loyal customer of this place. I ate here all the time and recommended to all my friends, even cleaned up my own table after every time I eat there.

However, recently I brought 6 friends here to the restaurant and was greeted with the worst attitude I've ever seen in my life! They refused to host 7 people although there were about 20 empty seats there at the time.

They told us we should have reserved which is okay, it makes sense. But when we asked why we couldn't just sit in the empty seats they continued to reply that it's not about the seats but more about the food, that they needed to prepare beforehand blah blah blah… I didn't really understand (due to their level of English) so I asked again "you mean you don't have enough food for 7 people? " (It was only 6pm), to which they replied "no, it's about the preparation, we need to make the rice… "? It's ramen that we want, not rice.

Anyway, I thought they meant the preparation time so I politely replied "it's okay, we don't need to be served all at once, we can wait for each person to get there food". And they also replied that it's not about that. At the end, they just gave up on explaining, because they can not provide a reasonable explanation.

I don't really care what their reason is that they can't serve us, we would accept it anyway and go to another place instead. But the problem was their attitude, the whole time they were "explaining", they were talking in a very disrespectful and arrogant tone (like they were talking to stupid people).

Seems like they don't need customers because they're so famous now, I guess it doesn't matter to them if they lost the profit on 7 bowls of ramen or 20,30 or even 100 more in the future.
I really do not understand the way they treat customers and everyone in my group was upset and confused. I guess we just stop supporting this place from now on because I wouldn't wanna support a business that operates like this.