Blocked caller still leaving voicemails

[Skelton]

A 020 number has been calling me and leaving voicemails, I blocked the number however they are still able to leave voicemails. I’ve sent a text to say they have the wrong number but it’s possible this isn’t a mobile user. Please help

[bristolian]

When a voicemail is left, the source of the voicemail is immaterial to any notification that the recipient gets.

If text notifications are enabled, they get one. If notifications are disabled, they don't. The voicemail spool icon appears regardless.