Can you post the full model number of the appliance please.
Ok are you able to turn the dial to cold?
Ok theres an issue in there.
After the fan was replaced did it seem to work even it was for a week or so?
Also are you able to do a full defrost on it for 24 hours?
What happens a lot on frost free is the evaporator inside the freezer builds up with too much ice and this effects the airflow into the fridge. As basically the fridge is an empty box, All the cooling is done in the freezer and the fan inside the freezer blows the cold air into the fridge. So if theres a big build up of ice on the evaporator then you loose the airflow into the fridge and you find the fridge starts to get warmer then it should.
So you may have an issue on the auto defrost side of the freezer thats causing this. As the appliance is only 3 months old and you have had a repair on it all ready i would insist on an exchange from them. Them will more then likely say they need to send an engineer out so when it comes out see if they can exchange it for you. As with these you have a 2 year warrenty so if it keeps breaking down they they have to replace it for you.
So try that route if you can and see if they will exchange it as its only 3 months old.
You very welcome. If you could remember to rate the answer that would be great.