Voicemail alert with voicemail deactivated

[#1]

I have my voicemail deactivated but receive a notification saying I have a message.  When I try to dial voicemail (to dismiss the notification) the call cannot connect and ends.  I then receive another notification! How can I resolve it?

[#2]

Hi, 

What handset are you currently using? I'm aware some handsets have an option within the settings of the phone which enables you to switch off the voicemail notification. -Ashleigh 

[#3]

Hi, I'm on Moto G3 running Android Marshmallow. There doesn't seem to be a voicemail notification option on the 'Phone' App. Attached is an image of the notification I am receiving (mobile number removed )

[#4]

Have you tried activating voicemail, check for and delete any messages and then deactivate?

[#5]

Thanks Jelv, I haven't.... is there an easy way to activate/deactivate voicemail from the handset?

[#6]

There isn't an option on the handset, so we'll need to do it from your account. 

If you dial 500 from your SIM or 0800 0791133 from another line, one of our colleagues will get this sorted for you. -Ashleigh