Visual voicemail in south Africa

I stay in South Africa, and I’m currently using Vodacom, which is the only carrier in South Africa that allows visual voicemail to be active, but I’ve been struggling to activate my visual voicemail for the past 4 days, and last night Vodacom told me the problem resides on apples side since Vodacom already has my visual voicemail enabled...I’m on the latest IOS, but my visual voicemail still prompts me to “call voicemail” instead of giving me the visual voicemail