How to access old voicemails which have already been listened to

Start by dialing 5001 on your phone, and pressing option 2 in the menu when prompted.

Your messages will be played in the order they were received, starting with the time/date stamp.

Handling options for new voicemail messages
Press 2 to repeat
Press 4 to delete
Press 5 to skip
Press # to finish

For even older messages, see Retrieving Deleted Voicemail Messages