A claimant need not be represented by an attorney before the Appeals Board, but if such person is represented the Appeals Board may award an amount for services rendered. Such fees shall not exceed $1,000 or 15% of the amount awarded, whichever sum is less, and shall be in addition to the amount of compensation awarded to the claimant. An attorney shall not charge, demand, receive or collect for services rendered in connection with any proceedings under this chapter any amount other than awarded as attorneys' fees under this section.