Any person who violates any provision of this article is guilty of a Class 1 misdemeanor. Any person willfully failing to pay oyster resource user fees to the Commission in the manner required by this article is guilty of a Class 1 misdemeanor. The Commission may maintain an action at law against any person required to pay oyster resource user fees to the Commission for the amount of oyster resource user fees due, plus interest, and a penalty to be added to the oyster resource user fees in the amount of six percent if the failure is for not more than one month, with an additional six percent for each additional month, or fraction thereof, during which the failure continues, not to exceed 30 percent in the aggregate.