Voicemail notification won’t clear

Hi

I have an iPhone 7 and am with Virgin mobile.

I recently had someone leave me a voicemail so I received a notification, called my voicemail, listened to the message and deleted it.

Days later, the ‘Phone’ app still has a red ‘1’ badge on it and I keep getting persistent notifications as banners and on my Lock Screen, despite me not having any voicemail messages.

I have tried calling my voicemail and it just says ‘you have no new messages.’ I have tried turning my phone off and on again several times. I have tried turning off ‘badges’ for the ‘Phone’ app, turning the iphone off, then turning the iPhone back on again and turning the Badge notification back on again and it reappears.

Please can anyone offer any alternative suggestions as it’s driving me crazy. Thank you.