If they had annouced the mall is gonna close, do you expect them to come to your table in the food court and give an application to take back your trolley. If you heard the annoucement, what stoppped you from going and collecting your trolley? Be flexible, and stick with the rules wherever you go. Dont expect the mountain to come to you, instead you try to walk over there, so that the life will be easy not only for you but for the others also...15 minutes may be a very less time for you, but it has its own value for the needy one.