It pays to have a smartphone. I create contacts, Scam1, Scam2, .... for all these numbers. More than one scammer number can be added under a contact. I check the option "Send all calls to voicemail" for these contacts. I am never bothered by these calls again as they all go to voicemail and scammers don't leave messages. I see all the attempts as missed calls but the phone doesn't ring. When I have time I delete the missed calls from the log to completely erase the thought of receiving these call. Have a nice day, good people and scammers.