If the fridge section is freezing things in there then its going to be a faulty control thermostat. This is a very common issue on these. As the dial you turn is actually a small thermostat board and then you have a main control board at the back as well.
When we get this fault Beko tell us to replace both control units and that will sort it. As either of them can cause this fault as theres no way of testing then so its a case of replacing then circuit boards in there.
The main board at the back is £27 and the thermostat board is £12.50 so there not that expensive compared to other circuit boards.
So its up to you if you want to try the thermostat board first and see if it cures it or you can just replace both at th same time as thats what were told to do by Beko.
If you need anymore info just get back to me.