Just switched to Verizon this week and have the same problem on my Samsung s7 and s8. AT&T provides a visual voice mail on google play store that works on unbranded phones. I am surprised that Verizon will not do not do it also. If not for the poor coverage of AT&T in my area I would switch back. Sales lied to me and said Visual voice mail should work. About time Verizon got with the program and provided an application like AT&T does.