[§271G-20]  Collection of rates and charges. No water carrier shall deliver or relinquish possession at destination of anyfreight transported by it until all tariff rates and charges thereon have beenpaid if such delivery or relinquishment without payment of all such rates andcharges has been prohibited or restricted by rules and regulations of thecommission, and if so prohibited and restricted, then delivery orrelinquishment shall be made only under such rules and regulations as thepublic utilities commission may from time to time prescribe to govern thesettlement of all the rates and charges, including rules and regulations forweekly or monthly settlement, and to prevent unjust discrimination or unduepreference or prejudice; provided that this section shall not be construed toprohibit any carrier from extending credit in connection with rates and chargeson freight transported for the United States, for any department, bureau, oragency thereof, or for any state or political subdivision thereof. [L 1974, c94, pt of §1]