How to clear voicemail notifications?

Hello all,

I have never had this problem before. Normally I get a missed call notification and also a voicemail notification. Once I call voicemail and listen to the message the notifications go away.

I had a missed call on Friday and since then I have 2 notifications showing on the phone icon and also on the voicemail icon. I’ve listened to voicemail and there are no messages but these two icons won’t go away. Is there a way of clearing this? I’ve tried turning off and on.