Who called from 4155207631

I'm on the do-not-call registry but received this call from a guy selling "securities," and asking to speak with the homeowner.  I told him we're on the DNC registry and asked him to remove us from his list.

Yes, twice on my cell phone. At first there is no one on the line, then when I say hello for the second time, a recorded voice says good bye and hangs up. I am wondering if they are up to something...

I have received 4 calls now from the phone number 4155207631. I am on the DNC list but still get these calls.

Cell phone rang and when I answered, no one was on the line.

Called my cell, when I answered no one was there