iPhone Voicemail Not Working?

Believe it or not, with all the texting and Email features on iOS people still actually get phone calls on their iPhones. An important part of phone calls is Voicemail. It appears that Voicemail can stop working for some iOS users. Sometimes, I wish it would stop working because of the Spam Voicemails I get, but I digress. If your Voicemail has stopped working on your iPhone, then read this article with suggestions of how to fix it.