I really need advice about a bad used car deal.

Here’s the situation.
My wife’s niece has a 2014 Ford Focus with the crappy dual clutch transmission. She got the car six months ago at a used car dealer in her town. The transmission broke soon after she got it and now it’s slipping again. The dealer repaired it once but refused to do it again and she still owes $8000 on it. The niece and her mom really got taken for a ride on this one. They are left paying for a car that isn’t worth nearly what they are paying for it and really isn’t repairable as this transmission is poorly designed and Ford was sued over it.
Any advice at all is appreciated.