Help me fix my fridigaire fridge

I have a side by side Fridge from Fridigaire. Last year, noticed that the refrigerator section is not getting cold while the freezer section was getting frosty with ice forming on doors. Called a technician and he did something (likely just defrosting) and charged $300. It was fine after that until a month ago when we started having the same problem. I am guessing its the defrost issue but I am not super hands on with this and now I am wondering if I should just replace with a new unit as the current one is 8 years old already. I have never bought a fridge before (always used the ones that came with the house) so also not aware of a good one I should buy if I need a french door fridge.