Dyson Purifier Cool Autoreact (TP7A) Relentless Whistling

I purchased the Dyson Purifier Cool Autoreact (TP7A) in June 2023. It worked perfectly for the first month, but then it started making an extremely annoying whistling sound that I can't get rid of. On most fan settings, the sound persists, rendering the device inoperable. I'm providing specifics to ensure that the scope of my frustrating experience is understood. To capture the noise, I even recorded videos while changing the fan settings. My initial attempts to contact customer service representatives via WhatsApp were futile. After watching the videos, I couldn't believe it when they said, "There's no problem with your device." So I went back to the store where I bought it. Just seconds after watching the video, the store staff confirmed that the noise was not normal and advised me to contact Dyson again. I struggled to persuade them to send the device for servicing during my second WhatsApp contact. I retrieved the box from home to save space and successfully packed it. I finally got the device to the service center via courier after jumping through hoops. They did, however, return it, stating that "no defects were found." The sound persists, much to my chagrin. I'm not someone who does extensive product research; I simply relied on a friend's recommendation due to my allergies. I was thinking, "Let's not complicate things; let's get the best." However, it turned out to be a letdown. I'd like to request a noise-free repair or a replacement for my device. Please, Dyson, make this right.