Section 764. Petition to terminate placement

Any parent or guardian or duly
  authorized  agency or next friend of a person placed under section seven
  hundred fifty-six may petition to the court for an order terminating the
  placement. The petition must be verified and must show:
    (a) that an application for release of the respondent was made to  the
  duly authorized agency with which the child was placed;
    (b)  that  the application was denied or was not granted within thirty
  days from the day application was made; and
    (c) the grounds for the petition.