Where a trader charges a fee in contravention of regulation 4 or any payee charges a fee in contravention of regulation 6A -

(a) any provision of a contract requiring the payment of the fee is unenforceable to the extent that the charging of the fee contravenes regulation 4 or 6A, and

(b) the contract for the purposes of which the payment is made is to be treated as providing for the fee to be repaid to the extent that the charging of the fee contravenes regulation 4 or 6A.