Mo. Rev. Stat. § 365.150: Violation a misdemeanor — penalty — recovery barred — correction of violation, effect.

1. Any person who knowingly violates any provision of this chapter or engages in the business of a sales finance company in this state without a license therefor as provided in this chapter is guilty of a class B misdemeanor.

2. Any person violating section 365.070, 365.080, 365.090, 365.100, 365.110, 365.120, 365.130, 365.140, or 365.145 shall be barred from recovery of any time price differential, delinquency or collection charge on the contract.

3. Notwithstanding the other provisions of this section, the failure to comply with any provision of this chapter with respect to any retail installment transaction may be corrected by the seller or holder within thirty days after the date of the sale, and, if so corrected, neither the seller nor the holder shall be subject to any criminal penalty or civil forfeiture under this chapter for the failure.