Food freezes in the fridge part even at the

The fridge gets its cold air from the freezer through a vent(damper) between the freezer and fridge.The fan in the freezer blows air through it. Make sure this fan is running. You may have to hold the door switch in for it to run. There is a flap you adjust with the fridge temp. control. Make sure it's opening and closing when you adjust the fridge temp.
The problem could be the electronic control if you have one or the mechanical linkages.

If it is freezing, either you need to turn both temp down to 2nd to lowest setting. Cold air does sink, so that is why crisper gets colder. There is a flap and vent for air between the fridge and freezer. The flap can get stuck in one direction, or the acutator that moves it can become faulty. A leaky door seal will also make the opposite compartment colder.