Who called from 7184120477

I got about four calls from them, and I'm on the national do-not-call list.

Number called twice an hour apart when I was away.  I called back and "the number is not in service."

same thing.. what is this?

J, they called me and said the same thing, but when we got disconnected they never called back and you can't get through to that number, so I believe it's a scam otherwise they would have called back.