Each member of the Planning and Zoning Commission shall serve until his or her successor is appointed and qualified. Members shall be removable for non-performance of duty, misconduct in office, or other reasonable cause by the Mayor upon written charges and after a public hearing has been held regarding such charges; a copy of the charges having been served upon the member so charged at least ten days prior to the hearing either personally or by registered mail, or by leaving the same at his or her place of residence. The member shall be given an opportunity to be heard and answer such charges. Vacancies shall be filled by appointment by the Mayor and shall be for the unexpired term.