talk with an agent re: Mobile Service

On July 27 and 28 I spoke with five different agents about a problem with my new Xfinity mobile service.  (Those contacts happened after length holds.) Three of those five agents assured me my problem was being worked on and that they would call me back to confirm the problem was resolved. None of those three agents called me back and my problem was not fixed. Now I am unable to reach a live agent to discuss the problem