Any interested person shall have the right to have the board call a hearing for the purpose of taking action in respect to any matter within the jurisdiction of the board by making a request therefor in writing. Upon the receipt of any such request, the board promptly shall call a hearing thereon, and, after such hearing and with all convenient speed, and in any event within thirty (30) days after the conclusion of such hearing, shall take such action with regard to the subject matter thereof as it may deem appropriate.