from http://www.straighttalk.com/controll...y=voicemailsetCan I change my Voice Mail pass code?
To reset your pass code, call your Voice Mailbox and listen to the tutorial. If there are no instructions for resetting the pass code, contact our Customer Care Center at 1-877-430-CELL (2355) to speak to a representative.
I don't see a way to reset it online. Sounds like though you'll have to call ST to reset it. Might be easier to contact them from Facebook.