21(1)
On making a determination under section 16 of this Act, a magistrates’ court may in its discretion make such order as it thinks just and reasonable for payment by any of the persons mentioned in subsection (2) of that section of the whole or any part of the costs of the determination ....
21(2)
Costs ordered to be paid under this section shall—
(a) in the case of costs to be paid by the debtor to the person in whose favour the attachment of earnings order in question was made, be deemed to be a sum due to the designated officer for the magistrates' court; and
(b) in any other case, be enforceable as a civil debt.