9. The worker who, without being entitled to it, receives all or part of an indemnity is bound to immediately reimburse any overpayment. The Commission must, in such case, recover such overpayment of deduct it from the amount of any indemnity to be paid to the worker. If such worker acted in bad faith, the Commission may add the amount of the interest to the deduction or reimbursement of the overpayment.