We have received several calls from 310-599-9113 this week, but when the call is answered no one says anything, not even an automated message; then after a few seconds of silence, we are disconnected.  When I call back the number, it indicates their regret because they only call business listings, and press "1" if you want your number removed from their calling list.

The removal process has been done several times and has not worked so far, because they keep calling, 2 calls today within 4 hours of each other.

I am looking for the next step to stop these annoying calls.  Please advise.