(a) Every mutual aid association, at the time of filing application for its certificate of authority, shall, by a duly executed instrument filed with the commissioner, on a form as designated and furnished by the commissioner, designate the principal office of the association in this state and constitute and appoint the commissioner, and his successors in office, as its true and lawful attorney upon whom all lawful process in actions or legal proceedings against it may be served; and the association shall agree that any lawful process against it which may be served upon its said attorney shall be of the same force and validity as if served on the association itself and that the authority thereof shall continue in force irrevocably as long as any liability remains outstanding against it in this state.
(b) Two copies of any process issued by any court of record in this state and served upon the commissioner or the person in charge of the commissioner's office by the proper officer of Montgomery County shall be deemed a sufficient service on the association; and the commissioner, promptly after such service of process, shall forward by registered or certified mail one of the copies of such process to the association at its principal place of business referred to in subsection (a) of this section.
(c) Within 30 days after the change of address of its principal office in this state, the association shall file written notice thereof with the commissioner.