I hate robo calls. A very annoying thing about my phone is that when I block a robo caller, it still lets the caller go to voice mail. So I went looking for a solution. Two apps might help. Truecaller for iPhone and Android, and Nomorobo for VOIP home phones.
Nomoromo blocks known robo and spam callers and you can add your
own numbers to block. Truecaller allows saved contacts and blocks
spam callers and telemarketers. It also searches for any name or
number not in your contacts, so you do not incorrectly block
numbers from a school or doctor's office. Bottom line, seems a bit
intrusive with checking your contact list, but blocks robos and