The funniest one is when my fixed line provider (let's call it P) calls me on my mobile phone (which is another provider) and ask me if I'm one oh their (P) customer :-) (the explanation is that the mobile/fixed businesses are separated to avoid monopoly and, since they can't share customer data ('cos of data protection rules), they have to ask them again :-))
Since then, I only get such calls from companies that got my details in exchange for some freebie. I tell them I'm not interested, and would they please stop calling me, and they do.
The only calls I got recently were in English with a heavy Indian accent, "Ilse Smid" or another stereotypically Dutch name, claiming to be from Microsoft Windows, and that my computer had alerted them that it had a virus... These scam calls all came from nonexistent Dutch phone numbers.
Telco has not been a free market, ever.
Competition is only a solution for problems where the telcos' interest and the consumers' interest align. And that's very rare.
Someday we'll have A.I. to screen calls for us, and hopefully it can also screen this highly-upvoted-but-worthless tripe from message boards for us.
If you pay upvotes and karma, you get unsubstantiated politicised arguments. The feedback mechanism rewards those comments.