(a) If, at the end of the crop year, the assessments collected for such crop year exceed the expenses incurred with respect to such crop year, each handler's share of such excess shall be credited to him against, and may be used for, the operations of the following crop year, unless such handler demands payment thereof, in which case his share shall be paid to him.
(b) The committee may, with the approval of the Secretary, maintain in its own name or in the name of its members, a suit against any handler for the collection of such handler's pro rata share of the expenses.