I cannot wait for some justice on that place.

Rough justice, as opposed to justice, will be administered.
Each foreign teacher teaching without a Z visa can expect a fine of 5000 yuan and a new 10-day * visa, type L, costing 160 yuan, issued once the fine has been paid, and it must be paid quickly! Failure to pay a fine promptly will result in imprisonment, followed by deportation. Moreover, all teaching contracts issued to illegals need not be adhered to by the illegal employer, so air fare reimbursement won't be paid.
As for the illegal employer, he can expect a fine of at least 50,000 yuan, even if he has employed only one foreigner illegally, and maybe even the school gate(s) will have to be locked, and his permission to hire foreigners will be withdrawn.