You have a system problem. Either a gas leak or compresor malfunction is your problem. I'ill bet that your unit is about two years old, maybe three. Please let me know if I'm wrong?
Call out the engineerss and they will run a mile or just re-gas it will will either work for a while or maybe not at all. demand a new fridge /freezer.
Hope this is of some help.
Simon.
robinjoye@simonjoy.freeserve.co.uk
Rob, September 2005