It is a basic legal principle that “court orders are meant to be followed.” You indicate that there is a court order in place, and that it is has not been adhered to. Even worse, there has been a negative impact on your child’s entitlement to various provincial and federal benefits, because of it.
In this situation, it may be possible to pursue a court order for contempt, but there are certain legal tests that must first be met. Specifically, for civil contempt to be established it must be shown that: (a) the order alleged to have been breached states clearly and unequivocally what should and should not have been done; (b) the party alleged to have breached the order had actual knowledge of it; and (c) the party allegedly in breach intentionally did the act the order prohibits, or else intentionally failed to do the act the order compels.
From the facts as described, it is difficult to determine whether these threshold elements can all be established. You should speak with a lawyer who can assist you with making that determination.