Except by procedures provided in this charter, the terms of the elective officials of the City shall not be shortened. The terms of elective officers of the City may not be extended beyond the period for which such officer was elected except that an elective officer of the City shall, after his/her term has expired, continue to hold office until his/her successor is elected and has qualified. The Council shall not grant or authorize an extra compensation to any city officer, agent or contractor, after the service has been rendered or the contract entered into. Nor shall the salary of any elective city officer be decreased after his/her election during any fixed term of office for which he/she was elected.