Check the fridge drawers for adjustable settings that control cold air. You can increase or decrease these vents by simply turning a dial or moving a lever. Next, is there ice forming on the inside of your fridge on the wall next to the freezer? If so, you have a leak. That ice is causing temperature drop in your fridge and messing with the thermistors sending wrong signals to the main board. Find the leak after thawing all the ice and repair that! If you ever had any of those geniuses coming to repair, they may have added a heater there instead of fixing the leak. Yeah, not too smart these guys. Fix that leak, remove that godddam heater and you should be fine.