Any certificate of registration issued pursuant to the provisions of this chapter shall be revoked by the license officer if the registrant is convicted of a violation of this chapter or otherwise becomes disqualified for the issuance of a certificate of registration. Notice of revocation shall be immediately given to the registrant by personal service or by certified mail to the address listed on the application and to the organization for which the registrant was soliciting. Immediately upon the giving of such notice, the certificate of registration shall become null and void and shall remain so unless the revocation order is rescinded. Upon revocation of any certificate the holder shall forthwith return the badge to the city. [Code 2000 § 16-11-16].