I have never had voicemail on my iphone. I have never wanted voicemail on my iphone. But it seems after a recent update, it automatically set up my voicemail and people are leaving me voicemails. Ive tried basic google searches but the answers there seem sketchy. And I cant find a simple activate/deactivate button.

How do I turn this off so people cannot leave me voicemails? I have ATT service if that matters.