Is my Prestige Fridge Freezer PRT 295FFCS repairable?

Prestige Fridge Freezer PRT295FFCS

Temperature in Freezer fluctuated over last few months, but righted on Fast Freeze . also cleaned grid at back !
Now Fridge part has similar problem.
Could this be thermostats (unlikely Both go ?)
OR coolant ?
OR is it dead !
Eleanor