LOL. Good one.
I deal with them by having caller ID and don’t pick up the phone, unless I recognize the caller name or number. If I don’t pick it up, it goes into voicemail, so if there is anything important they can leave a message. Telemarketers just hang up, when they get voicemail.
https://www.youtube.com/watch?v=fl5uhjJFTiE
The problem for me is we are doing some house renovation work and I’m contacting lots of suppliers and potential contractors. So I need to answer lots of unknown calls. It they show from far away I won’t answer them. But even that causes problems - I filed an insurance claim for water damage this winter and they are making calls without caller ID! Very weird of a big company to not have caller ID, especially an insurance company.