I also receive a lot of those (around ~5 a day, for more than 5 months already). It is really annoying and makes me wish I could just block numbers on my phone.
The internet myth is that this marks you as someone to keep calling (because you listened), but really they will stop.
I mean, I get ~1 unwanted call a week across a couple of phone numbers (that I answer and ask to stop). Other people are saying that they get a dozen a day and giving up on their phones. My anecdotes work for me.