Well, "this" is a bit nebulous. In pieces:
If the ex has collected more in support than was owed, it should be pretty simple to assemble records showing what was owed, and what was paid or collected, and to get a refund or credit when next in court (it would be a good idea to send a request first).
The order should indicate who has responsibility for buying what -- if he is not required to , but chooses to purchase items for the kids, it is considered a gift, but may provide "brownie points" in a later "he said/she said" -- so he should keep those receipts.
Accusations such as "belligerent" or "selfish" don't really mean a lot, at least not in isolation.
The questions boil down to "what does he want?" In terms of access, behavioral orders, time-share or economic adjustments, all are potential objectives of a family court motion. As with most such cases with lengthy histories, his best bet is probably a consultation with a family law specialist who can isolate his alternatives, let him pick what he really wants to pursue, and then find the most efficient means of getting there.
Answered on Mar 29th, 2014 at 7:07 PM