I followed these intrusctions:
Call your voicemail by holding the number 1 on your dial pad
Select option 3 to “Manage your greetings”
Select option 4 to “Manage your Extended Absence Greeting”
Select option 5 to block callers from leaving a message after hearing the Extended Absence Greeting
However this did not disable my voicemail, it works the same as before.
How can I disable my voicemail?