I received three calls today from this number at 4:51pm, 7:17pm, and 9:16pm, with no response any time I answered the call. When I tried calling the number, I received the error message that the call could not be completed as dialed. I'm reporting the caller to my service provider.
Same annoying experience. Just found instructions on how to block this number from AT&T
https://www.att.com/esupport/article.jsp?sid=KB408880#fbid=SvmrEY3dhUx
Activate/Deactivate Call Block
Listen for dial tone.
Press *60.
You will hear the announcement that gives the current status of the Call Screening list.
You will then hear recorded step-by-step instructions on how to add and remove numbers on your Call Block list, as well as how to turn the service on/off.