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For as far back as I can remember, my voicemail has been off by 3 hours. I've tried to get this fixed numerous times but nothing ever gets fixed. I have reset my modem, changed the time on my phone but it always changes back to the wrong time. That wouldn't be so back because I can subtract three hours from a time-stamp but more often than not, callers don't even get the option of leaving a message because when they call, they are told my number has been disconnected. This has ALSO been going on for more than 2 years with absolutely nothing being done on Cox's end. Nothing. Oh, I take that back. They're raising their bills next month. That's something. Something criminal if you ask me. I'm so over Cox. If my spouse was not intent on keeping their horrible service, I'd have left years ago. Crooks, criminals and con-men and Cox....all of them start with the letter C. Weird.
With regard to the 'number has been disconnected' message, log in to phonetools.cox.com and make sure that there are no unfamiliar numbers listed in Simultaneous Ring and/or Call Forwarding. If you are using your own answering machine, then the timestamp issue is with your phone, not with Cox.