Fridge freezer schreiber apm6855?

I am having loads of trouble with my fridge freezer. Freezer defrosting all food and reading -4 and fridge on h. Someone came out and replaced my motor in the fan costing me 150 quid and it still bleeps n fridge is reading +7 now n freezer -8. Nebody any ideas wot to do as the guy I got out to look at it in the first place keeps not turning up to relook at it and am desperate as I have 3 small children 1 of which is a baby. Thanks