This app was mentioned in 3 comments, with an average of 2.00 upvotes
If you have an Android phone, install Call Defender
https://play.google.com/store/apps/details?id=com.studiokuma.callfilter&hl=en
I installed this a while back: https://play.google.com/store/apps/details?id=com.studiokuma.callfilter&hl=en