If any commission merchant, dealer, or broker violates any provision of section 499b of this title he shall be liable to the person or persons injured thereby for the full amount of damages (including any handling fee paid by the injured person or persons under section 499f(a)(2) of this title) sustained in consequence of such violation.

Such liability may be enforced either (1) by complaint to the Secretary as hereinafter provided, or (2) by suit in any court of competent jurisdiction; but this section shall not in any way abridge or alter the remedies now existing at common law or by statute, and the provisions of this chapter are in addition to such remedies.