(1) If a service charge is not paid by the due date for payment, the person liable for the charge is liable to pay to AA (in addition to the charge) the penalty specified in the relevant determination under section 53, calculated on the unpaid amount of the charge from the due date for payment, and compounded.
(2) The penalty specified in a determination under section 53 must not exceed a penalty equivalent to 1.5% of the unpaid amount of the charge for each month or part of a month during which it is unpaid, calculated from the due date for payment, and compounded.
(3) Subsection (2) does not require the penalty to be calculated on a monthly basis.