Make sure in your CZZ contract two things are in print on it before you sign it:

"If the teacher does not receive his or her EXPECTED pay or within 24 hours therein, the teacher may at his or her discretion cancel the contract without penalty or threat of dire consequence."

"If any THREAT, (deportation, blacklisting, physical harm, unlawful seizure of passport, etc.), is made toward any teacher for any reason, these actions in actual fact cancel the contract."

From China Labor Laws regarding foreign teacher contracts.