Fridge/Freezer not working correctly - Beko?

My fridge freezer used to make very loud noises. Since these noises have stopped the fridge is not cold enough even when set on maximum. The back of the fridge is sometimes frozen and often slightly wet which I believe is normal. The freezer is also not cold enough. I put an ice pop in 2 days ago and it is still not frozen properly. I had to throw food away as some was soft, but other food looked dried out with lots of ice crystals around. It should be a frost free freezer but there is a large build up of crystal ice at the back which I have removed once but it has returned.

The model is CA7015FFS. We have contacted Beko and it is not one of the ones that have been having the faults. It is about 3 - 4 years old.

Thanks in advance