This in regards to the Korean International School in Shenzhen.

I am not at all if this is the same place, but if it is you are probably lucky.

About three years ago a FT from Chengdu left to go work.

It was supposed to be an international high school. The courses included English, Chinese, and Korean.
Supposedly they paid about 17,000 a month (why my friend left to go to Shenzhen).
It wasn't in town, but way out in the sticks. When I say sticks, I mean 15-20 on foot to the nearest restaurant/general store, but they at least had cold beer.
All of the students were living in on campus dormitories and confined to campus.

He was back after one maybe two months.
Half the FT left after a month or so, the half were from the Philippinnes and busy looking for jobs before they quit.
Let put this first, he wasn't a groveler and has been to China several times and speaks Chinese reasonably well.
He described the place as hell the worst of Chinese and Korean management systems combined.
He was supposed to have an apartment, instead they were sticking all the teachers in the student dormitories.
The students were all rich kids from Seoul. He described it as basically a reform school for the well off.
Students were expected to study from 8am to 10pm etc.

The worst was the head master that was running around screaming and yelling at every one all the time. They had one old Korean man that had to check and make sure the students weren't ditching class or sneaking out of their rooms at night. When one of them got caught, he got his ass chewed and it was his fault. The guy either had a stroke or heart attack and was dead in four weeks.

Unrealistic expectations on students and teachers, and then when they don't do well, you are a bad teacher, and they are a lazy teacher, etc.

Combine that with all the other crap they usually pull here. You dont get the apartment promise. Your salary is late, but only after you lead a rebellion to get paid, and then there are still deductions or it isn't the full amount promised, etc.

This was quite a while ago, so I am not doing it justice. But you get the point.

So you just may have been lucky. Pity that poor Korean teacher.