My Zanuzzi/Electrolux fridge freezer has stopped freezing?

My Fridge Freezer started sounding the alarm to say it was not cold enough regularly. It has now stopped freezing and keeping fridge items cold. I fiddled about with the settings and it started working again, but it lasted about a week and has now stopped again. The light is on but the alarm is not sounding to say its not cold enough.

Please help, can this be repaired or is it better to replace it.