none of these things are enforceable. I'd be surprised they even went to the effort to cancel your z visa. The owner of a school I spoke to said it was such a hassle to cancel a visa he would only do it if somebody had really pissed him off.

Wait you're not even in the country yet. Ah that makes it trickier. You might want to apply for another job and they haven't cancelled your visa. How can you apply for another job? Hmmm I'm not sure maybe somebody else can answer. Like Sorrel says I would just say somebody in your family got ill and you cannot leave for China. maybe there is someway you can find out if they have canceled your visa. If they haven't you could work somewhere in shanghai. If they have you can start the process again i think.

The contract will not be binding in your own country

schools in shanghai are expensive to set up and usually follow visa regulations correctly. most are part of big branches.

Just say you showed the contract to a legal friend.

Then ask questions.

Is this contract legal under Chinese law? My friend says no.

I dont like this part, can I change it?

Do you apply the 5 year law? What is the 5 year law.

This contract is in English. Is it legal?

Trust me on this. Chinese employment law is fuzzy. No one understands it. Start quizzing them, and they will decide you are more trouble than they are worth.

And do it all via email. Your webcam is broken. No more skype.

If they get nasty, no problem. Are you using a gmail account? Ask them how they can do that when it is bannned.

Do they have a license to employ foreigners, or a buisiness license? Ask for a copy so you can scan the matrix code ( wechat has a handy scanner where it will tell you all public domain info attached to a business license, including deposited capital).

If you keep asking questions, they will soon forget you exist.

But anyway, come to Guangzhou, its much better than Shanghai.