1. Contact the child's defense lawyer: the lawyer can provide information on the progress of the case and explain the reasons for the delay.
2. Contact the local public security bureau: check the progress of handling the case and find out whether there are other procedures to be handled.
3. Patience: The judicial process may take time to deal with the case, but you can follow up regularly to ensure that your child gets proper legal aid.
Summary: The prison term of online fraud varies from case to case. To know the progress of the child's case, you can contact his detention center or local court. If you haven't heard from me for a long time, you can consult a defense lawyer or the local public security bureau. Please note that the above answers are for general guidance only, not legal advice.