False advertising

Today at 12:15 I visited KFC at V&A Waterfront and ordered myself Red deal for one. As per the description it clearly says 1 piece chicken, small chips and snack burger. When I placed my order and advised the cashier which piece I prefer she refused, I was unsure why as it clearly states 1 piece and not which piece. The cashier called the manager by the name of Mische without listening to me she also advised I cannot choose what I want even if it says 1 piece. I told her that I visited KFC at Century city and Promenade and I never had a problem however she said her branch is different and walked away without even apologising. I never expected this sevice from KFC Waterfront