Our fridge keeps changing temperature no matter what setting we leave it on. This morning it said minus 5 on our fridge thermometer and some stuff was frozen but it was fine yesterday (~4-6 degrees). If we leave it on a warmer setting it can oscillate between 5 and 12 degrees. Is there anything I can do or do we just need a new one? It’s only 2 years old so didn’t expect it to die so quickly. Can’t find the original purchase details to check if there is any warranty still.