the pin numbers from KHCONF are usually the area code followed by three more numbers.
There's an administrator pin that establishes the conference.
There's also an attendant pin that gives you the total number of listeners.
Then there's two other pins, one for listening only and one for listening and commenting.
If they change the listening pin they usually don't change the other pins.
It may take some time and repeated dialing, but you could guess at the last three numbers after the area code and get in on the conference with luck.
The local administrator of the account can log into https://report.khconf.com/
and see who called in and for how long. If they see any strange numbers, like
numbers outside the area code they'll try to do a reverse look up to see who the
phone belongs to, and if they can't find out they will discuss the need to change
the pin number, then publishers who want to listen in have to call the Coordinator
for the new pin before the meeting. That's the standard procedure locally.