Upon receipt of a completed application and fee, the Commissioner of Consumer Protection shall issue and deliver to the applicant a certificate to engage in the business for which the application was made; or refuse to issue the certificate. The commissioner may suspend, revoke or refuse to issue or renew any certificate issued under sections 20-670 to 20-680, inclusive, or may place a registrant on probation or issue a letter of reprimand. No application for the reinstatement of a certificate which has been revoked shall be accepted by the commissioner within one year after the date of such revocation.