My nearest and dearest tend to use mobiles these days. My landline phone has the ringer switched off so these calls never bother me. I can see missed calls on the phone, with the calling number. I have become rather adept at recognising bogus calls but if I see one I am not sure about, I will first Google the number. Well known spammer numbers will usually show up there.
Whenever I have forgotten to have the ringer switched off and get caught by one of these nuisances, tell them to hang on a moment when they ask for me (or whoever), lay the phone down on the table and go back to watching the telly. After half an hour or so, I might replace the phone and switch the ringer off again.