I just received a call from this number and went into my cell phone provider account and added it to the blocked caller list.  

I have gotten 5 calls in less than 3 weeks from these people and every time I have asked not to be called again. They just hang up on me when I say to stop calling.  I also have my number registered on the do not solicit list so I'm not sure how they are legally able to keep calling (guess I'll be reporting them there too).

Do these calls cause any harm?

First call today home security.  Female caller.  Called back 3 hours later but I missed call.  

This number has called me several times and they never leave a message.  If I can get to the phone in time, I block it.  So annoying.