When a banking customer exercises the right to cancel he may only be required to pay, without any undue delay, for the service actually provided by the firm in accordance with the contract. The amount payable must not:
exceed an amount which is in proportion to the extent of the service already provided in comparison with the full coverage of the contract;
in any case be such that it could be construed as a penalty.
The firm may not require a banking customer to pay any amount on the basis of this rule unless it can prove that the banking customer was duly informed about the amount payable and, in the case of a contract which is a distance contract, in conformity with the distance marketing disclosure rules. However, in no case may the firm require such payment if it has commenced the performance of the contract before expiry of the cancellation period without the banking customer's prior request.