Sounds strange, the post office should be responsible for their drivers actions. I would continue to complain, if the immediate supervisors do nothing then I would try to contact someone above them. Several years a ago there was a mail person who was stealing packages (in a city near me, I saw it on the news), the postal service launched an investigation and found out he was stealing packages and reselling the items online and in local pawn shops. If the postal service continues to do nothing talk to you neighbors and find out if they are having similar problems, if so go to a news station in your area and see if their investigative reports would look into it. I'm truly sorry you are going through this. Liars are probably very triggering for most people.