A call handler should work for you. Go to Unity web admin > Call Handlers. Create a new call handler and set the After greeting action to "Send caller to" Hang Up. Record a greeting and give the call handler a DN.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...