Mountainman

Malwarebytes does Nothing to block calls by itself unless you list in the App the call numbers you wish blocked. However, there is an App "AT&T Call Protect" I find incredible. It self identifies and auto blocks telemarketers. spam risk calls, fraud calls and much more. You can decide if you want them totally booked or change the settings by call type to allow them to go to your v-mail. I find, as a Premium member of Malwarebytes for several years, that the product is useless both on scanning my computer and useless on my phone. It does Nothing. I would try AT&T Call Protect. I

Call your carrier and have them limit the number of rings, as you indicate "still rings constantly" or put the phone in a DO Not Disturb Setting at least for iPhones. Also whoever said to report each number to Malware is also correct. I do all three and have seen much improvement. And if I don't recognize a caller ID then don't answer I don't care if is was someone that really wanted to reach me as they would leave a voice mail. PS: Apple Sr Techs recommended Malwarebytes to me for a nation-wide Safari scam which they could not fix. WHA-LA ! Malware stopped it immediately.