Hi, I´m just write this as info about the fridge, as I had the similar problem into the partment I at present rent. I of curse doesn´t know the the fridge Liz is talking about are a similar one, but in case...
Some fridges has a freezer section and a fridge section but only ONE compressor to create the cold for both of them. That means there´s a General Thermostat, mostly placed in the fridge section, for the whole unit.
The cold is generated in the freezer section and from there it must to be a channel down to the fridge section. This channel have a Manual Regulator, where one can choose how much cold air will go down to the fridge.
Many aren´t custom with how such units works, not even the owner, so often both the thermostat and the manual regulator in the freezer section is put into wrong position. Mostly the Thermostat and the Regulator has these options.
THERMOSTAT (placed into the fridge), the words can however differ.
1-MIN the cold will be at the minimum, not good at all
2-NORMAL the cold will be normal both in the freezer and the fridge
3-MAX the cold will be at maximum, only for use during a short time
4-INVERTAL the unit will run 24 hours a day, which isn´t good at all
REGULATOR (placed into the frizeer)
1-MIN minimum cold in the frezer as the channel is fully open to the fridge
2-NORMAL for the best of both freezer and fridge
3-MAX maximum cold in the freezer and minimum to the fridge
The problem for such Freezer/Fridge is; if the Regulator for air down o the fridge section is set on MAX for too long time to have a freezer as cold as possible, it will start build up ice in the back, where the cold is generated. If it goes on for too long time, less and less cold will be generated as a whole because of too much ice is built up (behind the wall).
As a result, the fridge will be too warm to use for food and the freezer section will not be colder that a fridge. Service is urgent needed!