Fridgemaster fridge noisy and not cooling

Please help.

I have a Fridgemaster MTL55300 fridge, bought 5 years ago. Lately, it has become very noisy (sound of compressor running continuously) and is not cooling. The top back wall ices up and the bottom of the fridge is warm.

I have cleaned the condenser coils on the back of fridge . I even emptied the fridge and left the door open all day yesterday. I cleaned everything, emptied the drip tray, checked the drainage hole wasn’t blocked, etc. This fridge doesn’t have a fan.

I don’t know what else to try.