1. Open WeChat and search for "Black Cat Complaint" to see a small program with the same name.

2. After finding the program, open it and click "Complaint" to enter the complaint interface and bind the mobile phone number.

3. After binding the phone, the protocol interface will pop up. Read the agreement carefully and click Agree to enter the complaint interface.

4. Enter merchant information, transaction information, order number and rights protection amount in the complaint interface.