I have a Magic Chef refrigerator , model ctb1925drw. Recently the freezer stopped defrosting and ice was accumulating in the freezer and was colder than usual even when the thermostat setting was changed. Also the fridge portion stopped cooling and the food began to spoil .
Take the control section loose and locate the defrost timer. advance it to see if it will go into defrost. If it does that’s probably the problem. Post your results and we can check elsewhere if need be.
Hope this helps
Nat