Called twice today. No message left.

I keep getting calls from this number, and when I answer there is never anyone there.  I have gotten 10 calls and it is only 12:30 pm.  Is there some way to stop these unwanted calls?

I keep getting calls from this number almost every hour during weekdays, and sometimes two calls in a row each time! So annoying especially when I'm in a meeting.

I just got a call from this number. it was for a weight loss pill

Have received to calls in the last hour. No message left..........which usually means sales or someone asking for contributions to a charity (real of not).