Fairphone 5 microphone rumble noise

I bought the phone directly from Fairphone as a refurbished phone. The IMEI (both) are recognized as Fairphone 5 refurbished. But that’s it, dead end. No link to another page or anything. Isn’t a refurbished Fairphone still a Fairphone?
I will try the CS chat tomorrow. I have read that there is a human between 10 and 12 h. The AI started talking french to me for some reason.