(b) Every such summons shall be served at least five days before the return date, either by personal service made by any person over eighteen years of age or by registered mail, but return acknowledgment is required to prove such latter service. Failure to obey such a summons so served shall constitute a misdemeanor. The fees for the attendance and travel of witnesses shall be the same as for witnesses before the circuit court.
(c) Any circuit court shall have jurisdiction, upon application by the commissioner, to enforce all lawful orders of the commissioner under this section.