My iPhone is being remotely controll by hackers trying to extort money

I have a new iphone XSmax. It is not jail broken. When i make calls there are other people on line talking in the background. I disable both bluetooth and wifi, yet they get turned back on. I have been threaten to pay money or they will brick my phone.

The remote users can hang up my calls, exit my apps, click on the wrong thing, I have used the built in screen recorder to document. I have also tried using secure vpn.

I have called both Apple and my carrier. Apple says the only thing I can do is reset the phone to factory. My carrier has re-provisioned the phone. It will work fine for a few days and then the ghost in the phone takes over.

This also was happening on my previous iphone8 . I think the phone is getting compromised via bluetooth. Is there anyway to remove the bluetooth chip or some way to monitor when software is added to the phone. Apple support refuses to believe an non-jailbrake phone can be compromised. Wiping the phone every couple of weeks is not a solution. Bluetooth security failures has been documented.

I am open to any suggestions.

thanks

-c