Ga. Code § 40-1-161
The commissioner may, at any time after notice and opportunity to be heard and for reasonable cause, revoke, alter, or amend any limousine certificate issued under this part, or under prior law, if it shall be made to appear that the holder of the certificate has willfully violated or refused to observe any of the lawful and reasonable orders, rules, or regulations prescribed by the commissioner or any of the provisions of this part or any other law of this state regulating or taxing motor vehicles, or both, or if in the opinion of the commissioner the holder of the certificate is not furnishing adequate service. An administrative hearing shall be conducted in accordance with the procedures for contested cases under Chapter 13 of Title 50, the "Georgia Administrative Procedure Act," and the provisions of Code Section 40-1-56.
OCGA § 40-1-161