(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 the date of the determination, file with the Commissioner a petition for a hearing on the determination. The petition shall set forth specifically and in detail the grounds upon which it is claimed the administrative determination is erroneous. Hearing or hearings on the petition shall be held by a referee appointed for that purpose, at times and places as provided by rules of the Board. Notice of the time and place of the hearing or hearings shall be given electronically or by ordinary or certified mail to the petitioner.
(b) After a hearing pursuant to subsection (a) of this section, the petitioner shall be promptly notified electronically or 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 of the decision by the Board within 30 days after the date of the decision or unless the Board, on its own motion within the same period, initiates a review of the decision.