Ladies handing out free Coca Cola 200mL cans at Parramatta Westfields, Level 1, where Westfields joins to Parramatta station underground (opposite Priceline).
I imagine once they run out of stock, they will disappear, so this offer is probably valid for another half an hour / hour if you are in the area!
Also at Westfield Doncaster, ground floor near Smiggle