Firstly is there any sign of power going to the fridge, does the fridge light come on when you open the door?
Secondly does the radiator at the back of the fridge freezer feel warm?
The most likely cause is either someone has accidentally switched the fridge off on the counter, turned the thermostat in the fridge to the off position or the fuse in the plug has blown, however if the fridge light comes on when you open the door, that rules it being a related to the supply of electricity to the fridge.
Anything short of changing the fuse in the plug will require an engineer visit, to diagnose the fault.
Please let me know how you get on checking if the fuse and switches, and if this doesnt work, please provide your postcode so I can suggest a suitable engineer to repair your fridge freezer.
Hello I am just following up from last week, do you still require assistance, if the above suggestion has resolved your issue I would appreciate if you could rate the service received.