A very common problem with frost-free freezers is that the air ducts inside the casing at the back become choked with frost and ice. This prevents the freezer section being cold enough.
Of course, your problem might have an entirely different cause, but since this one is so common, and so easy to DIY rectify, you might give it a try.
Turn it off
Open the freezer door. Take out all the food and eat it, or double-wrap it and put it in a stack of large carboard boxes to delay defrosting, or put it in your spare freezer.
Pull the freezer away from the wall so you can see the evaporation dish for melt water, on top of the motor.
Observe the water dripping both inside the cabinet and into the dish at the back. Keep sponging the water up. Clean out the dish and its drainpipes, which will probably be full of dust, fluff, mould and grime.
Wait until all the dripping has completely stopped so you are confident that all the ice has melted (this may easily take 24 hours as the ducts are buried in insulation.
Dry off, restock, turn on, cook any food that has melted, eat the icecream or throw it away.
