Let me give you tips:
Wherever you are, there's always a promising way to find out the upscale luxury shops in town. Check out those 5-stars business hotel in downtown, they normally have those brand names in their shopping arcade. Also ask the employees in those shops to know other places they are located.
Actually, not only finding out the location, I can as well get things from those shops for free if I want. There are always tricks to do anything if you are willing to exercise your mind.