A truly dishonest business cheating all the way on purpose. You shouldn't have worked there at all if you are none of the "unqualified" teachers. You could actually have done much better.
1. I worked there for 3.5 years
2. Hire Foreigners Illegally
3. HR told me they bribe government
4. If you do work legally, they will not let you leave with a thirty days notice in accordance to Chinese Law...they will not give you the cancellation documents, and they might withhold salary.
5. Many teachers are unqualified.