2012 CTS. When I have the bluetooth connected to my phone, the instrument cluster shows my phone number. The navigation screen shows a single button: "Hang Up". Pressing the "Hang Up" button on the navigation screen or on the steering wheel only results in a voice confirming "hang up the phone". How do I return to Radio or any other audio functions? The "Audio" button doesn't do anything. My phone always has bluetooth on. It gets automatically connected to the car. And radio just stops. Help ... 
Many thanks!
/dan
Many thanks!
/dan