Before enacting the zoning ordinance or any amendment thereof, the chief legislative body shall hold a public hearing on the ordinance or amendment, at least fifteen (15) days' notice of the time and place of which shall be published in the official municipal journal or in a newspaper of general local circulation. No change in or departure from the text or maps as certified under §42-6-103 shall be made, unless the change or departure is first submitted to the planning commission or office and approved by it or, if disapproved, receive the favorable vote of a majority of the entire membership of the chief legislative body.