Good afternoon my name is ***** ***** appears the thermostat or temp sensor in your freezer has failed.
Before looking at fitting a replacement it is worth double checking you havent enabled the super freeze function, however in the most cases a new sensor\thermostat will resolve this issue.
If you provide the model number and postcode, I can give you the cost of the part and suggest an engineer who can attend to replace the part.
Good evening, I havent heard from you in a while, do you still require assistance?
A replacement thermostat\sensor is around £35 from companies such as eSpares, if when the engineer attends and finds the sensor is working properly, it may well be the control board which is around £120 which needs replacing.
Based on your area I would recommend EDA Repairs on 0800(###) ###-#### they charge a fixed price of £75 to cover inspection and all labour costs, if after inspection you do not want to proceed with repair the cost is only £45.
Good evening, I havent heard from you so wanted to follow up to see if you still require assistance for your query?