Yeah, in North America we're pretty much at the mercy of spam and shady businesses. There are some laws against spam and robocalls but almost no resources are devoted to enforcing them and there are tons of excuses. Unsurprisingly, politicians created exemptions for political robocalls. I expect that algorithms find numbers and if you ever answer one they'll never stop. I get between a couple and a half dozen such calls per day. About the only relief has been to set my phone to "Do Not Disturb" on the setting that allows calls only from my contact list.