(1)    The department or permit officer may refuse to grant permits in the case of minors who seem physically unable to perform the labor at which they are to be employed. They may also refuse to grant a permit if in their judgment the best interests of the minor would be served by that refusal.

   (2)   Whenever it appears to the department that a permit has been improperly or illegally issued, or that the physical or moral welfare or school attendance of the minor would be best served by the revocation of the permit or that the failing school performance of the minor would be remedied by the revocation of the permit, the department may immediately, without notice, revoke the permit. The department shall revoke a permit if ordered to do so under s. 938.342 (1g) (e). If the department revokes a permit, the department shall, by registered mail, notify the person employing the minor and the minor holding the permit of the revocation. Upon receipt of the notice, the employer employing the minor shall immediately return the revoked permit to the department and discontinue the employment of the minor.