FLEX makes a terrible noise and the screen turns black every few seconds

My FLEX makes a terrible noise and the screen turns black every few seconds and have still not been able to use it since it arrived two weeks ago. And yes, I have powered it off and on again, I have reset it multiple times, have changed all settings, and have also tried different HDMI inputs and cables nothing has corrected this issue. There is no direct support for the FLEX on the Xfinity site and the "chat" just loops and offers no support. It is defective and I need a new one ASAP.