Cold air enters the fridge through a damper or vent between the freezer and fridge. The evaporator fan in or behind the freezer blows the air through. There is an adjustment to open and close this vent to allow more or less cold air in.
Your control may not be opening and closing the vent. Find it and see if it moves when you move the control. | 
Fridge is freezing food 
fridge is freezing my food solid even though it is set on 1. How do i fix it?
