Recently I've been having trouble with getting to my voicemail. I entered the passcode I set, but it said it wasn't valid and to try again. I've tried multiple other codes, I've changed it a couple times, and none of them work, I just get the "*number* is not a valid passcode. Please enter your passcode and try again" message.
What exactly does it want as my passcode? Letter, numbers, both, and how many characters?