What should you do if you suspect somebody has used your credit card? Start by reading this article.

Prevention

Firstly, a few tips focused on prevention:

1. Keep your credit cards secure both at home and on your person.
2. Shred anything with your credit card number on it.
3. Don’t sign blank credit card receipts.
4. Avoid giving out your credit card information.
5. Don’t use your credit card online unless you’re sure the site is legitimate and safe.
6. Report lost or stolen credit cards immediately.
7. Review your billing statements each month.

Dealing with problems

If you do suspect a transaction has taken place that you did not authorize:

1. Collect as much documentation and detail as possible to prove that your card has been used by somebody else.
2. Call the bank immediately to report your credit card as having been used by somebody else. See below for credit card hotlines for major banks. Many have English-language services. 
3. The bank will freeze your card.
4. Dispute any unauthorized charges that have been made to your account.
5. You may wish to file a police report, although this can be time-consuming.

 
Hotline numbers for major banks providing English-language services 

Industrial and Commercial Bank of China        95588 
Agricultural Bank of China                             95599 
Bank of China                                              95566  
China Construction Bank                              95533  
Bank of Communications                              95559
China Merchants Bank                                 95555 

Useful Chinese words and phrases            

source:one-stop