The zoning regulations imposed and the districts created under authority of this act may be amended, supplemented, changed, modified or repealed from time to time by resolution of the Board, as it affects its jurisdiction, but no such change shall be made without public notice and hearing and the filing of a report and recommendations upon such proposed change by the Commission.

All projects or matters that fall within the purview of the duties of the Commission, as specified in this section shall be referred to the Commission for investigation and report before any final action shall be taken thereon; provided, however, that if the said Commission fails to make an investigation and report on any matter or subject referred to it for a period of thirty (30) days, such failure shall be considered a refusal to approve the proposed plan or project and the Board shall be under no obligation to wait longer for reports or recommendations concerning said projects.