The Commission shall provide by ordinance for the collection of all public utility rates and charges made by the city. With respect to water, the city shall have all the powers granted to cities by Public Act 178 of 1939 as amended. When any person, firm or corporation shall fail or refuse to pay any sums due on utility bills, the service upon which such delinquency exists may be discontinued and suit may be instituted by the city for the collection of the same in any competent tribunal.