Ok I'll try thatso you disconnected the battery and it came back up still stuck in a call?
please verify
if so then you very well may need a scanner that can talk to the modules and see if it is communicating, if not then you could try re-programming it and if that does not work then yes it might need to be replaced. other options are check the harness and see if there is maybe a loose connection. if a reboot does not work then there is probably no "easy" fix
and you can get used modules for a hell of a lot less than $800
Thank you