LG DUALCOOL 12K BTU – False Specs And Ineffective Cooling

I purchased the DC12RTH LG DUALCOOL™ Sirius 12K BTU Inverter Wi-Fi Air Conditioner from lg.com.tr. The product was delivered by cargo. During installation, the service team noticed that the bottom cover was broken. They said they would replace the part, and I agreed. The air conditioner was installed. After installation, during the test run, I told them that the air conditioner was not cooling properly, but they claimed it would cool over time and left. I tested the air conditioner for a couple of days. Even when the outdoor temperature was 23°C, it couldn’t lower the room temperature below 23°C. The room is 24 square meters and has double-layer insulation on both the inside and outside. I called LG, but they said they couldn’t send the service immediately and scheduled a visit for 10 days later. They assured me that I wouldn't lose any rights. Ten days later, the service came and claimed that there was nothing wrong with the unit, and added that new-generation machines don’t perform very well anyway. They told me I should resolve the issue with LG and leave. I called LG again, and they said they could only send service again if I paid for it. I refused and said I wanted to return the air conditioner. They told me I had no right to return it and that there was nothing more they could do. I trusted the LG brand when making this purchase, but I never expected to encounter such an unprofessional company. The product doesn’t function as expected — it performs more like a 7,000 BTU unit rather than a 12,000 BTU unit. And the after-sales support is non-existent. I feel like I have been scammed by LG.