AAF garnesing almost $300 out of my wifes check without notifing either one of us springdale arkansas

Me and my wife was buying a 2000 pontiac grand am off aaf in siloam springs we had the car not even 6 months and we put over $800 in this car and they told us if we had bought any parts for any automobile off them to bring the recipt to them and we would work out a deal on the car payment well we did and they didnt hold up there end of the deal so we got tired of putting work into it so we vouteerly let the cargo back they even came and got it well about 2 weeks ago my wife job notifyed her that AAF sent paperwork to them saying they was  garnishing garnishing her check every two weeks well at that time they took $195 and that was on the 28th of april and on the 12th of may my wife got payed again and then the held out $248 and they never notifed us by mail or by phone. So now i have no way of knowing how much more there going to take how can they even do that without taking us to court for the garnishing of my wifes pay check we are a family of 8 and shes the only one that works cause i stay home with our disabled daughter now we cant hardley make it on what she has left after they take whatever they want out of her paycheck this is not right.