we just moved into a home with a Samsung iDCS 28 D phone, and cannot figure out how to change the voicemail recording from their greeting to a new greeting. Everyone who calls and gets voicemail hears the old owner's name and phone number and so they think they have the wrong number and hang up. Also, when I go in to retrieve any messages (although they are all hangups!), it says something about a "code 400" Please help!