1. Off-hours: 12304 The manual customer service is busy during holidays, Spring Festival travel rush peak hours and other peak hours, so I can't get through, and I can't get through until working hours on weekdays.
2. Line or system failure: The telephone line or system may fail, making it impossible to make a call. At this time, you can try to call again at other time periods, or choose other contact information for consultation.
In short, if 12304 can't get through, you can try to wait for the end of peak hours or the number of calls, or consult through other contact methods.