Sorry for typing this in English, but this is ridiculous. If a person is that crazy, then there ought to be a caretaker.
Fortunately for that lunatic, the OP wasn't that hysterical enough to grab a bottle and hit his head.
I don't condone violence against mentally disabled people but the situation might have called for it since the staffs weren't helpful.
Btw, that's ridiculous, laughing at a woman being sexually assaulted? What? How does that make sense?
It is infuriating when outsiders see the situation as being comical when it isn't at all.
Sincerely hope the staffs will be punished by the superiors and please find suitable staffs, maybe?
What's the point of doing a service kind of job if your head is not in it? Same goes for securities too.
Hope the OP is doing okay.