Tried to block this number, comes up invalid number!

Received a call from this phone.  Have no clue who it is.  I was unavailable to answer the call at that time.

Calls about once a day. First time I answered it as it was my area code, but only silence. Now I ignore but it keeps calling. I almost always ignore calls that have generic location in the ID, and this shows that it is a good strategy.

Keeps calling my cell phone even tho on the DO-NOT-CALL list??? When I try and call the number back, Verizon claims it can't place the call as dialed. It is getting very annoying to say the least!!!!!