No person doing business in this Commonwealth, or any agent or attorney of such person after having discharged any employee from the service of such person or after any employee shall have voluntarily left the service of such person shall willfully and maliciously prevent or attempt to prevent by word or writing, directly or indirectly, such discharged employee or such employee who has voluntarily left from obtaining employment with any other person. For violation of this section the offender shall be guilty of a misdemeanor and shall, on conviction thereof, be fined not less than $100 nor more than $500. But this section shall not be construed as prohibiting any person from giving on application for any other person a truthful statement of the reason for such discharge, or a truthful statement concerning the character, industry and ability of such person who has voluntarily left.