A defendant who has been sentenced to pay a fine may at any time petition the court which sentenced him for a revocation of the fine or of any unpaid portion thereof. If it appears to the satisfaction of the court that the circumstances which warranted the imposition of the fine have changed, or that it would otherwise be unjust to require payment, the court may revoke the fine or the unpaid portion thereof in whole or in part.
N.J.S. § 2C:46-3