(a) Any employing unit aggrieved by an administrative determination affecting its rate of contributions, its rights to adjustment or refund on contributions paid, its coverage as an employer, or its termination of coverage may, within 30 days after date thereof, file with the Commissioner a petition for a hearing thereon, which petition shall set forth specifically and in detail the grounds upon which it is claimed the administrative determination is erroneous. Hearing or hearings on such petition shall be held by a referee appointed for such purpose, at such times and places as may be provided by rules of the Board, and due notice of the time and place of such hearing or hearings shall be given by ordinary or certified mail to the petitioner.

(b) After hearing as provided in subsection (a) of this section, the petitioner shall be promptly notified by ordinary or certified mail of the findings of fact, conclusions, and decision of the referee. The decision of the referee shall be final unless the employing unit or Commissioner makes application for review thereof by the Board within 30 days after date thereof or unless the Board, on its own motion within said period, initiates a review thereof. (Added 1961, No. 210, § 10, eff. July 11, 1961; amended 1965, No. 76, § 1, eff. May 26, 1965; 1989, No. 8, § 6; 1991, No. 82, § 6.)