Short and simple: 

I DO NOT WANT VISUAL VOICEMAIL.

Regular voicemail is, and was just fine. This  app is frustrating and causing problems, especially when it solves NO problems at all. 

I cannot disable it any way I've tried. 

How do I get rid of it. I simply want the 'old' style of calling in, listening and using the dial-pad.

I have found the app and the system pops up 'you cannot disable visual voicemail'.