Arçelik Air Conditioner Cooling Issue: Lack of Service Support

I purchased an Arçelik air conditioner, and despite it being only a year old, it has started to stop cooling. I called the service twice, and each time they came, they claimed there was no issue with the cooling without conducting any proper checks.
When I contacted them again, they told me that the unit was insufficient for my workplace. If it was indeed inadequate, why didn’t they inform me not to install it when they came for the initial assessment? They are not taking this matter seriously and are essentially lying; the air conditioner is not functioning. Even customers are questioning whether the unit is on or off, while it is indeed running but not cooling.
I am extremely disappointed with Arçelik and feel regretful about my purchase. I expect better service and support for a product that should work as intended.