The City Council shall, before suspending or revoking any license and at least 10 days prior to the date set for hearing, notify in writing the holder of that license of any charge made, and shall furnish the licensee with a copy of the complaint and afford the licensee an opportunity to be heard in person or by counsel in reference thereto. This written notice shall be served by delivery of the same personally to the licensee or by mailing the same by certified mail to the last known business address of the licensee. If the City Council shall determine that any licensee is guilty of any violation of any of the provisions of this ordinance, the license shall be suspended or revoked for a period of time as shall be determined by the City Council.