2. Collect evidence: collect evidence of charges due to undisclosed information, including payment vouchers, communication records and related documents. These evidences will help to support the claim and prove that the rights and interests have been infringed.
3. Contact relevant departments: consult and complain to departments responsible for information disclosure such as government information disclosure office or industry regulatory agencies. Explain the situation to them, provide relevant evidence, request to intervene in the investigation and take corresponding actions.
4. Initiate a complaint or lawsuit: Consider initiating a complaint or lawsuit. According to the specific circumstances, submit complaints or litigation materials to the relevant administrative organs or courts to safeguard the legitimate rights and interests.
5. Media exposure and public opinion supervision: arouse public concern through media exposure and public opinion supervision, and urge relevant power departments to pay attention to and take action on the issue of undisclosed information charges.