Worst service received today at Mr Price Tembisa Mall

I went to exchange my clothes at Mr price they let me wait in the long queue then when I got to the till I received the poor service, the lady told me that the exchange system was offline, why didnt they inform us while we were still waiting in the long queue, she showed no interest in helping me just gave me my clothes back then I had to leave. I'm so mad at the fact that I expected a good service since they have just opened on Friday.