Any person, firm or corporation who violates any provision of this chapter or does anything declared herein to be unlawful shall be guilty of a misdemeanor and fined not less than five dollars ($5.00) nor more than fifty dollars ($50.00). The second conviction of a person, firm or corporation engaged in the business of moving household goods or personal effects in bulk, or pianos, for hire in the City shall cause a revocation of the license granted to such person, firm or corporation. Thereafter no such person, firm or corporation shall carry on such business in the City during the remainder of the period of time for which such license was granted.