Who called from 7206192001

They call me also do you know who's calling from 720-619-2001

This unnamed caller calls several times a month and leaves no messages. I'd like them to stop calling.

I received a call from this number 3 times a week. I have no idea who it is, a message has never been left. I have the option on my phone to rejected a call from specific numbers, I have done so. My phone will show a missed call but it also indicates call was rejected.