The top freezer cools like a fridge, the bottom fridge is warm

I bought my refriderator a year ago. It has a top freezer and a bottom fridge. Initialy it used to work. Then some months ago, the freezer started cooling like a fridge while the bottom was warn. Then some month later the freezer started freezing while the bottom was still warm. After a few weeks, it the freezer became like a fridge and the bottom is still warm. I have gone through the troubleshooting manual and I am now convinced the product is defective. This is surprising as I used to hold LG in high esteem and almost all my household appliances are LG. Pls I would really appreciate your help in this case