From CFA institute:
Enrollment and registration fees are nontransferable and nonrefundable. Application and payment must be received by CFA Institute by 11:59 p.m. Eastern time on or before the application deadline. Full refunds are available within two business days of payment if you change your mind. Due to fluctuating exchange rates outside our control, we cannot guarantee that the exact amount paid to CFA Institute will be the same amount (in other currency) returned. Registration deferrals to the next available exam are also considered on a case-by-case basis for life-threatening or very serious illnesses (candidate or immediate family), natural disasters, and mandatory military service. This does not guarantee a deferral to any candidate for any condition but instead provides CFA Institute with the discretion to determine which deferral requests it approves and denies. Candidates awarded a deferral are responsible for all applicable new curriculum charges. Deferral requests must be received by CFA Institute prior to the scheduled exam or within 10 U.S. business days after the exam date.

So the best for u would be to cancel it within 48 hours, and register for the next. Otherwise, u have to convince CFA institute u are under an emergent condition, namely, 1. life-threatening or very serious illness to u or your parent, or child, or spouse, 2. natural disaster, guess u'll need earthquake or tsunami for this purpose, 3. mandatory military service, which is obviously inapplicable for China, unless CFA official is ignorant.