In the UK the Telephone Preference Service (TPS) is the register for saying "I don't want unsolicited live sales or marketing calls". "Making you aware of" on behalf of a business is a marketing call, so there is no "loophole" to fix.

If the business ignores the rules, there is little that can be done legally.

UK law differentiates between businesses, charities and individuals. I do not know how it is done in other countries, but in the UK you can't pretend that a lone individual ringing you is a "marketing" call, no matter how much you dislike the other person or their topic. If it is a person ringing on behalf of a business, it's a business or marketing call, and therefore subject to TPS.

I do not know how registered charities (not businesses) relate to TPS. I haven't received a call from a charity that I can remember, but my grandma once did get a call from the RSPB whose telehandler seemed oblivious to her having suffered a stroke with speech difficulties, and subsequently arranged for a boatload of bird seed and pamphlets for her to distribute (which would be impossible!).

TPS also does not apply to individuals, which is why any individual can lawfully ring someone else, unless the calls are repeated (harassment), but again that doesn't fall under TPS.

You can become "ex-directory" to stop your number being listed, but this doesn't stop organisations just iterating phone numbers incrementally hoping to find someone.

I do not know if you're in the UK, but you can see the definitions of problematic calls and what you can do according to OFCOM here: https://www.ofcom.org.uk/phones-and-broadband/scam-calls-and...

For visitors to your door, you can put a sign up. I have. It stops all visitors. I also have a video doorbell so I can decide whether I bother answering the door.