Faulty fridge-freezer

[mnbcv]

The fridge section of my 15 month old Caple fridge-freezer is freezing up with the control set to minimum. Two new sensors and a new control panel fitted but the problem persists. Door seals good. The freezer section works fine. Any suggestion as to how I can repair it?

[pops91710]

My fridge was doing the same thing until I cleaned all the accumulated dust off of the condensing coils.