No disbursing officer of the City shall issue any order or check for the payment of money for any work, matter or thing contracted for or ordered by the Council or any officer or employee of the City which shall have been so contracted for or ordered wholly or in part in excess of the amount which shall have been previously set by ordinance or resolution as the limit of expenses of the department to which such work, matter or thing belongs, or in excess of the amount available in the City treasury for such payment. The foregoing provision of this section is intended as a restraining provision, and it is further declared that no act of such disbursing officer shall be in anywise held to render valid any debt contracted by or on behalf of the City in violation of the Constitution and laws of the State. Any such officer of the City who shall violate this section, shall upon conviction, be subject to such fine and imprisonment as shall be fixed by the court, and shall be disqualified from holding office.