iPhone 8 plus and recently upgraded to iOS 12.0.1 how can I restore Voicemail?

[iMore Question]

I have an iPhone 8 plus and recently upgraded to iOS 12.0.1 and now my phone is showing no voicemail messages; however, I had several voicemails saved before the update. (Several sentimental messages from my mother and father who have both since passed). Any help would be greatly appreciated!

 

[wilber1]

I would check with your service provider ,am sure they could help with voicemail .