(1)  A code must specify that if a regulated entity overcharges a customer for the supply of a regulated service because of –

(a) an error by the entity; or

(b) inaccurate metering by the entity of the amount of water supplied to, or sewage removed from, a property of the customer –

the regulated entity must, within a period, after becoming aware of the error or inaccuracy, that is specified in the code –

(c) inform the customer that the customer has been overcharged; and

(d) refund to the customer the amount of money by which the customer has been overcharged, together with the interest that the code specifies is payable to such a customer.

(2)  A code must specify that a refund to a customer is to be made by a regulated entity –

(a) in accordance with any reasonable instructions of the customer; or

(b) if no such instructions have been received by the entity from the customer, by crediting the amount of money to the next account for the customer.