But no enforcement in the quiet zones? Then that is a simple failure of service level agreement and should be pursued through the normal complaint procedures. If an organisation says they do something, then they should do it!
And yet, with clear indication that certain areas are quiet zones, people and organizations should be able to rely on the common decency of people. People will in 99% of cases respect any 'no smoking' signs without enforcement from a 'shusher', so why not the 'be quiet' signs?