(a) The commissioner may hold hearings for any purpose within the scope of this title deemed by him to be necessary.
(b) The commissioner shall hold a hearing if required by any provision, or upon written demand therefor by a person aggrieved by any act, threatened act or failure of the commissioner to act or by any report, rule, regulation, or order of the commissioner, other than an order for the holding of a hearing or an order on hearing or pursuant thereto. Any such demand shall specify the grounds to be relied upon as a basis for the relief to be demanded at the hearing, and unless postponed by mutual consent, the hearing shall be held within 30 days after receipt by the commissioner of demand therefor.
(c) Pending such hearing and decision thereon, the commissioner may suspend or postpone the effective date of his previous action.
(d) This section does not apply as to hearings provided for in Chapter 13 of this title.