If a representative charges a fee for representing a claimant and an issue as to the amount of the fee is raised by the claimant, the representative, an administrative law judge, or a member of the board, the representative shall receive no more for the representative's services than an amount approved by an administrative law judge or the board. If no issues as to the amount of such a fee is raised, the fee shall be deemed approved. The fee approved by an administrative law judge may be reviewed by the board.