Hoover Fridge Freezer not working, model HMA 28CX?

hi,

My hoover fridge freezer bought 7 years ago is not freezing the food at all and the fridge is not keeping anything cold at all. I have not left the door open but it is kept in a cold environment in the kitchen. I have tried changing the thermostat inside the fridge to the highest setting 5 i believe , they say in the booklet that 0 is off and normally 3 should is fine here in the summer months, Now it is winter, they recommend placing the setting at4-5 cos there is no heating in the kitchen...

any help or advice, the light comes on when the door is opened and there is the normal noise out the back of the machine but no freezing going on ???