How can I turn my freezer down

[veneeroftheweek]

We have recently moved into a place with a fridge freezer. I noticed that things weren't frozen properly so checked with a freezer thermometer and it's only -10. Trouble is I have no idea where the thermostat is. There's something inside the fridge but that only seems to control the fridge not the freezer. I've pulled out the drawers and can't see a thermostat. Any suggestions? I don't know the model number, but it's a Zanussi.

Have you looked for a sticker inside somewhere that gives the model number?

The adjuster will be on the outside of the freezer even at the back.

Yes, I've looked for the sticker but it's not there. It's pretty old I think.

I'll check the back as well. Thanks.