Wow.. Sorry to hear this. If what you say is true, unless there's some third element like chargebacks in this mix, there's really no reason I can see that they wouldn't pay you. If the needs for the payout they set forward were met, in my opinion, ethics dictates they should pay you that payout up through the point when they requested to switch the revenue model.
I understand no one wants to lose money, but $200 doesn't seem like a large hit to take to maintain a business relationship. It also sounds like you've been trying to work this out for a while, so it seems you've made your best efforts before bringing it here. Just doesn't make sense.
