I believe the NPO is only required to account for all monies coming in and out of the org - it's not required to track accounts at the player level.The organization is a registered non-profit, but the accounting is a bit - for lack of a better term - "loose". The amounts being disputed are relatively small (about $100 per family), but the player fees were paid into the player accounts via the organization's checking account.
Was the checking account for just that team? I'd say your chances are much worse if the money was commingled with other teams.