(1) If a quantity of diesel in respect of which a subsidy has been paid is sold by the supplier in contravention of a condition of the supplier's registration, the supplier shall pay the Commissioner—
(a) if payment is received within 21 days after the date of the repayment notice—the amount of the subsidy, plus interest; or
(b) if no such payment is received within 21 days after the date of the repayment notice—3 times the amount of the subsidy, plus interest.
(2) This section does not apply in relation to a subsidy if the supplier is liable to pay an amount under section 34 in relation to the subsidy.