Am assuming you are saying there is no problem with the freezer but the fridge is too warm
if yes have you tried a total defrost
on most of these units ( and I don’t know 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} about this one ) they use cold air from the freezer to cool the fridge. sometimes ice build up blocks the air duct and stops it working
switch off, open both doors and leave open for 2 days
you will have to plan for your freezer contents while you do this maybe run it down over a few days
then switch on and see how it goes
Dave