Hi,
Attention dual citizenship holders if you enter the country on one passport you must leave the country you cannot leave, work or study using your second passport without first existing the country.
Regardless of the fact that you may have used your second passport previously to live, work or study in China. Changing passports also renders your previous residence permit, health certification and student cards invalid according to Yunda. These documents must also be changed over so the details must match those in your other passport. In other words they have to be done again.
According to the local police under Chinese law they don't recognize the right to hold the citizenship of more than one country. So for legal purposes you are treated as two seperate entities. That is to say that if you are registered as at an address as an Australian citizen but if visited by the police at home and asked to provide proof of residence and your previous registration was done using the details of your second passport. It's up to the police to use their discretion in the matter as to whether you are legally registered according to the law.
To sum up if leaving the country and re entering using a different passport you are required to go through all the registration formalities again in duplicate.
PS. Your school could terminate your previous enrollment and re enroll you as a new student make you pay all one off fees applicable to new students again. They also don't recognize dual citizenship holders either so you can continue your current enrollment and keep the same academic record.
Finally no negotiation will be entered into over the matter.