Beko CDA543FW - possible timer issues?

Hi All

I have a few questions regarding this UK model fridge freezer unit which i hope somebody will be able to help me with. :) I have little knowledge of this field so please bear with me.

To sum it up, the fridge stops working every 2-3 days, the only sign of life being the fridge compartment light coming on when the door is opened.

I thought it was a faulty timer originally but this was replaced a few days ago. Despite this change, the fridge freezer still appears to have the same problem.

I will try to sum it up as below.

For a few days, fridge and freezer work as intended. The thermostat being set to 3 out of a 1-5 scale. The compressor and the fan in the freezer compartment come on periodically and all temperatures are fine.

Then, at some random time (within 2-3 days later), it will be obvious that the fridge is too warm. Checking the compressor reveals that it is stone cold which means it hasn't been active for quite a while. Winding the timer onwards by 1 notch turns the compressor back on, and the freezer fan starts to spin. Fridge freezer will then cool down and work fine for the next 2-3 days until it happens all over again.

Now, i have played around with the timer. It seems to have 14 notches. I noticed that when the fan and compressor aren't active when they clearly should be(because the compartments are too warm), turning the timer on 1 notch activates compressor and on the 14th turn, it turns off again. One notch forwards turns it back on again and so on.

Presumably, this 14th postion where it seems to get stuck, the apparent off/defrost cycle notch, is only a defrost stage? and it should automatically click past this notch and on to the 1st notch again, maybe after 30-60 minutes?

So far, i have left it like this for 5-6 hours before having to click the timer forwards by 1 notch again so that the food doesn't start to go bad.

Does anybody know if these 14 clicks correspond to 14 hours or some other intervals, and if so, how long it should stay on the last one for so that food doesn't begin to thaw?

Any ideas? Thanks in advance for any input and suggestions.