Blocked numbers can still leave voicemail

My mobile phone is an LG with Android. I'm a long time Norton user of course. I love that I can block the zillions of spam calls but they are able to leave voicemails. They call so often and change their numbers (something I'm not sure you can prevent) almost every time they call me, then leaving voicemail after voicemail. I spend sometime every evening deleting messages. Can we block callers better? So they cannot leave messages? Thank you!

Hi, Brandy77.

I think this is something that you have to contact your wireless carrier about.