Broken fridge sold to customer

My mom bough a fridge at OK in Scottburgh, only to find out that the fridge was on display for the longest time. They did not tell her that it was the one on display. It’s been 2 months and the fridge is now giving us issues. It is not cold and the runners are loose. The freezer is overproducing ice. They do not want to take it back yet she was not given the option to agree or not if she wants the fridge that was on display.