An assessment agreement shall be filed with the Federal Maritime Commission and is effective on filing.

If a complaint is filed with the Commission within 2 years after the date of an assessment agreement, the Commission shall disapprove, cancel, or modify the agreement, or an assessment or charge pursuant to the agreement, that the Commission finds, after notice and opportunity for a hearing, to be unjustly discriminatory or unfair as between carriers, shippers, or ports. The Commission shall issue its final decision in the proceeding within one year after the date the complaint is filed.

To the extent that the Commission finds under subsection (b) that an assessment or charge is unjustly discriminatory or unfair as between carriers, shippers, or ports, the Commission shall adjust the assessment or charge for the period between the filing of the complaint and the final decision by awarding prospective credits or debits to future assessments and charges. However, if the complainant has ceased activities subject to the assessment or charge, the Commission may award reparations.