I have a scenario that I would like you to weight in on.
I'm travelling and I would like to disable my voicemail. If I go into my device and disable call forwarding to the voicemail number of my provider, will that essentially disable voicemail or do I have to have the carrier disable it?
Set your phone to not forward calls. Your voicemail will be there, but your calls won't go there until you change it. The carrier can also change it for you. Sprint/verizon like to charge for forwarding changes in my experience.
Some carriers do not allow you disable call forwarding. The easiest way to do it is to call your provider and ask them to remove the voicemail service from your account whilst you're away.
I go with dc/dc, they would have to remove the voicemail service from the acct most likely. I would block call forwarding if you don't want to get calls while way either.