Telephone Icon Missing from Info Menu

2008 Prius with Nav/GPS system and 6-CD audio system. Around 30K miles, Bluetooth failed, and the Telephone Icon no longer appears on the Info Menu. Service Menu shows no version number for Bluetooth software, suggesting it somehow was deleted. Two local Toyota dealers don't know how to fix it. Toyota Customer Service gave wrong instructions: to eject the map data DVD and then reinsert it to reboot the system. That did not correct the problem because the map data DVD has only map data, not Bluetooth. Is there an internal hard drive on the center console unit that holds the software for Climate, Audio, Display, GPS, and Bluetooth? There must be. I need instructions on how to (a) reload the software, or (b) reboot the system to get software to reload. One local dealer said I had to replace the entire unit. Uh huh; that's like buying a new laptop because someone deleted Skype.