more than likely it is blocked with ice in the back of the freezer compartment (behind the white rear panel. the cause of this could be numerous, the top shelf could of been overstocked with packets blocking the grilles at the back, the door of the freezer or fridge could of been left open by accident for an extended time or there could be a problem with one or more of the temperature sensors -usually in the freezer. what you can do yourself is to unload it and turn it off at the mains and allow it to defrost manually for 1 to 2 days leaving the freezer door open if possible. when you turn the electric back on have both doors open when you plug it back in and after 5 seconds you should hear the fan in the back of the freezer come on briefly, (this checks the fan is working) though it will then turn itself off until the freezer gets down to minus 5 . close both doors and leave, after about an hour the freezer should be at minus 20 but the fridge wont get down to temperature for another couple of hours. this should work but dont go rushing to the supermarket and spend lots of money filling it back up in case this only temporarily cures your problem. if it lasts a week you are usually safe. ps check the freezer door seal for kinks allowing air in usually the bottom of the freezer door next to the hinge sometimes creases at this position though on this model you will need an expensive new door as the seal cannot be replaced seperately. good luck
knowitall, May 2009