All Star Towing Illegal towing after my car broke down and a cop helped push the car into the post office parking lot dallas Texas

On Tuesday, February 25, 2014 my broke down on Ferguson Road here in Dallas, Texas.  A man and a Dallas police officer pushed my car into the parking lot at the post office on ferguson.  The next morning I went with a friend who was gonna help me get it started and my car was not there.  I called the post office and spoke to a man who went to investigate what happened to my car.  I received a call back from the post office employee and he stated that he saw a tow sign over by the CVS Pharmacy and called the number and they had my car.  I called All Star Towing and the manager stated that my car was towed because I could not leave my car in a private property parking lot.  The post office is not a private property parking lot, also the sign is totally displayed over by the CVS Pharmacy and the over stores, not by the postal office.  The sign is facing Ferguson road and not the parking lot.  There was no way to see the sign and it was not posted in the post office parking lot.