(a) Any person who shall wilfully and intentionally violate this chapter or engage in the business of a sales finance company in this State without a license therefor as provided in this chapter shall be fined not more than $500.
(b) A wilful violation of §§ 2907, 2908 or 2909 of this title by the seller or holder shall bar recovery of any finance charge, delinquency or collection charge on the contract.