I worked for Gina a few years ago and had a somewhat similar experience.
I lasted three months before giving her a months notice. After I gave notice, she said she wanted me out of the apartment immediately. I refused. The next day she had all the utilities in my apartment turned off. I went to the school to talk to her about it. She told me I was fired effective immediately. She then threatened to kill me and said this in front of Amber and a receptionist. She then called the police on me! I waited for the police to arrive and tried to tell them what happened. Gina was still screaming at me in Korean so they made her leave the room. The police were sympathetic to my plight but because Amber and the receptionist refused to back up my side of the story there wasn't anything the police could do for me. The police escorted me out of the building and apologized for Ginas' behaviour.
The next day my utilities came back on. I don't know why. I stayed in the apartment another two weeks.

Gina owed me about 4.5 million won when I left. She refused to pay me any of it. I went to the Labour Board. Some of the people there were quite nice, others didn't give a shit about me or what had happened. After three and a half months of phone calls, translators and a weekly trip to the Labour Office in Seongnam, they arranged a meeting for Gina, the owner and myself. The Labour Board guy refused to use my translator. He had Gina do the translating! Needless to say, I got totally screwed. Out of the 4.5 owed to me, I only received 1.5 million.

If she doesn't pay you, try the Labour Board. You could also get a lawyer but all the ones I contacted wanted at least 2million as a deposit.

Good luck!

Also, when I worked there she was trying to buy the school. In my three months, I believe all of the other teachers quit or were fired. Speculation had it that she was trying to get the sale price down.