The commissioner, after providing notice and conducting a hearing in accordance with the provisions of chapter 54, may revoke or suspend the closing-out sale license of any person for (1) conduct of a character likely to mislead, deceive or defraud the public or the commissioner; (2) engaging in any untruthful or misleading advertising; (3) utilizing the services of a promoter who was not registered under this chapter during the time of the closing-out sale, or (4) violating any provision of this chapter relating to closing-out sales or any regulation established pursuant to section 21-35i or 42-110b. In addition, the commissioner, after providing notice and conducting a hearing in accordance with the provisions of said chapter 54, may impose a civil penalty of not more than five hundred dollars for each offense. Each violation with respect to each separate item of merchandise shall be deemed a single offense.