Angry customer

Today at 17:59 I went to spar did my weekly shopping for my daugters school supply get to the till pay an amount of R200 for the snacks, I then go back and get Cadbury twix bars which clearly stated on the shelf it was R17.99 the cashier then went to the manager who came and said with attitude very rude and abrupt by law she cannot give it for the price we see but for the original price of R27.99 a bar which I the customer saw R17.99 the name of the manager is Crystal Dippenaar at spar kensington 12th avenue as well as telling me I can complain or just so what i feel like doing upon leaving the store she and the one cashier still has the audacity to laugh at me.

If this matter is not resolved i will be taking my case further.