No employer or employe shall be charged fees of any kind in any proceeding under this act by the department, the board, or any of its officers or agents. Any individual claiming compensation in any proceeding before the department, the board, or referee may be represented by counsel or other duly authorized agent; but no such counsel or agent shall either charge or receive any greater fee for such services than is approved by the board. Any person who violates any provision of this section shall be guilty of a misdemeanor, and, upon conviction thereof, shall be sentenced to pay a fine of not less than fifty dollars nor more than five hundred dollars, or be imprisoned for not more than six months, or both.