It could be a couple of things. If your refrigerator is not cooling the first thing to check is the condenser fan motor. It is located at the bottom of the refrigerator in the back near the compressor. Pull the refrigerator out and put your hand near the bottom of the refrigerator and see if you can feel the fan blowing. If the fan is not running and the compressor is replace the fan. If the fan and the compressor are running check the freezer if you dont hear the fan in the freezer running it is bad replace it. If the evaporator fan is running and you see frost on the back wall of the freezer you have a defrost problem. If you see frost that would be like the tip of the ice burg behind the freezer wall is a big block of ice that will need to be thawed out. You will have to turn off the refrigerator and leave the freezer door open for 4 or 5 hours. Once you do that the refrigerator will run good for a few days. That’s when you can call Appliance Repair Specialist out to make that repair for you.