Here's a piece of entirely unsolicited, but very well informed, information security advice.
If you have a corporate voicemail system, go and change your voicemail passwords, today, to the most secure password the system will allow (that you can remember easily enough); then delete any voicemails you have with private information on them.
Oh and don't make your vmail passwd or pin the same as any other passwd or pin. Really, do NOT do that.
Then do it again at least every week for the next... oh, call it six weeks... maybe two months... And check and delete your voicemails every few hours, or at least once a day.
Trust me on this one.
There's a very good chance you'll be receiving an email telling you to do this from your corporate voicemail manager in the next few weeks.