Visual Voicemail

[Heathery12]

Constantly bombarded with this message, probably 20 times a day 

Sorry, your number doesn't support Visual Voicemail, so we can't set it up yet. Please contact your service provider for help.

[jonsie · Accepted solution]

You need to toggle the visual voicemail off in message settings

We’re just customers like you but it sounds like you’ll need someone to access your account which can’t be done from here. If you message O2 using the links below, they should be able to help you with this

[Ricciw8]

Hi, I recently encountered these constant text messages from O2 straight after switching from an iphone over to an android device. The O2 customer services team made some changes to their system settings i.e. changed my account so as to be seen as an Android and not IOS, and it has since been resolved. I have no idea as to what visual voicemail is and probably don't need it, but thankfully the text messages from O2 have now stopped. Hope this helps.

[BobHarvey]

Just found a blog post which says the feature is supported:
O2 launches Visual Voicemail on Google Pixel 3 and... - O2 Community