Beko AC Not Cooling,Faulty Installation Led to Warranty Issues

I purchased a Beko air conditioner from an online site, but unfortunately, it does not cool effectively. Additionally, I did not receive the necessary invoice and warranty certificate. The installation team that came over did not vacuum the system, and they miscalculated the room size, leading to incorrect installation. They didn't connect the air conditioner properly, so I only had the chance to test it a month later. When I finally did, I found that the vent wasn't opening. They said the installation needed to be redone from scratch and moved the unit to a different location without updating the system entry. This caused further issues, and I had to wait for them to reinstall it, during which the air conditioner was damaged. Despite their repeated attempts, the system was still not entered correctly, and the air conditioner doesn't work as it should. It fails to cool the room, even with the door closed, leaving us sweating. The service team neglected to perform a proper vacuum installation, as advertised on their website. Moreover, they failed to send the warranty certificate, providing only the user manual. I had to escalate the issue to the Consumer Arbitration Committee, but Beko's customer service remains unresponsive. This has been a frustrating experience, and I regret buying this inadequate and expensive device.