Clicks
Shop closes earlier than advertised

I arrived at the store at approx 15h52 and the shutter was closed, and security guard showed me that shop was closed. I showed her through the window that there was just over 5 mins left still. She was rude and refused to let me in. Should the store not close the doors exactly at 16h00 as its advertised on window? Next time I'll shop at Dischem as Clicks doesn't need my business.