Iceline fridge freezer.

Hello! A few months ago I acquired an ‘Iceline’ frost free, fridge freezer. Not sure of its age, but a few years old now. It does its job fine, but it seems to have an insatiable appetite for electricity. I’ve tried the thermostat setting at either end of its range and have now got it turned to its lowest setting, but it still has the compressor running for ages and ages. (It consumes about 5 units of electricity in any 24 hour period) It does go off, followed by some bang, crash, wallop noises and then restarts to follow the whole procedure over again. The seal on the freezer door is damaged and some ice does form on the goods placed on the top shelf in there.
Any ideas (apart from the local tip) please?

Len.