Section 12. The commissioner may suspend or revoke any license issued pursuant to this chapter if he finds that: (a) the licensee has violated any provision of this chapter or any rule or regulation adopted hereunder or any other law applicable to the conduct of such business; or (b) any fact or condition exists which, if it had existed at the time of the original application for such license, would have warranted the commissioner to refuse to issue such license.
Except as provided in section thirteen, no license shall be revoked or suspended except after notice and hearing pursuant to chapter thirty A.
A licensee may surrender any license by delivering to the commissioner written notice thereof and such surrender shall not affect the civil or criminal liability of such licensee for acts committed before the effective date of such surrender. No revocation, suspension or surrender of any license shall impair or affect the obligation of any pre-existing contract between the licensee and any other person.