35 ILCS 110/7a
It is unlawful for any serviceman to advertise or hold out or state to the public or to any service customer, purchaser, consumer or user, directly or indirectly, that the tax imposed by this Act or any part thereof will be assumed or absolved by the serviceman or that it will not be added to the selling price of the property transferred as an incident to a sale of service, or if added that it or any part thereof will be refunded other than when the serviceman refunds the selling price and tax because of the merchandise being returned to the serviceman or other than when the serviceman credits or refunds the tax to the service customer to support a claim filed with the Department under the Service Occupation Tax Act or under this Act. Any person violating any of the provisions of this Section within the State shall be guilty of a Class A misdemeanor.
35 ILCS 110/7a