Hi edzdrl,
If you are unable to access your voicemail give us a call at ATT. This could be due to a number of issue. My first gut instinct that I would have one of us reps check would be to see if the IMEI on you account is updated. If it is not then there might be compitability issues. If that is up to date, the next issue I would have us check is to make sure that you have the correct format of Voicemail on your account. Most Iphones require visual voice mail (This does not extra on the account) to work properly. Finally if neither of those are the issues I would have the representative perform a trouble shooting session and see if there is something in our system that needs to be resest or if advance trouble shooting is require. Hoep this helps
(^ W^)/