Store closing 15minutes earlier

I was at your Jabulani mall store on Tuesday the 21st April. To my surprise when I got to the tills at 17h30 there was only one cashier there, and two of them were cashing up. We then stood in the que for more than 10minutes cause the lady in front was waiting for her lay bye. When we started complaining the manager (Mokoena) just looked at us and walked away. When I got to the door at exactly 17h45 I then realised that the store was closed. I then asked the manager why the store had closed so early, he then answered me and said cahiers cash up 15minutes before so that at 18h00 they leave. I then said to him that's not whats at your door. Meaning Ackerman's is misleading its customers. Please attend to this, it is totally unacceptable.