The game is super fun!!! Congratulations!!
I would ask an option to disable the [??] calls, I don't enjoy trying to memorize or finding the number in the Directory. Or maybe let the directory for only emergency calls and that is easier to search. Ooor maybe just make a column for the emergency numbers, so it's easier to find but you have to be quick for this ones.
Also, probably adding more visuals when a call is done. I usually forget to disconnect cables because the light is not really that easy to see. Maybe keeping the card while the call is active so the card has like three states "incoming", "connected" and "finished" so when you see the big "FINISHED" message you now can remove the cables to give space to more calls.
Thanks for making the game! I really enjoy playing it:)