Unpleasant treatment

Good day...the service I got from shoprite in South gate it's not pleasant at all .i was ****** with an amount of R20 by the cashier named Vusimuzi. Sport check was done but to my surprise they said he was over and yet he had 30 rand pn his hands.i bought things that amounted R266.27 and gave the cashier 300 and realised that I had 17 rand and told him to give me the 50 rand and I'll give him the 17 and he rep**** by saying I'm confusing him and he then asked me for a change of two 10 rands which I did give and he never gave me my 20 rands instead he took my 10 rand that I gave together with the R23.80 that added up to R33.80 but when he was taken to cash office for sport check he had R30 in his hands which is my 20 he was supposed to give and the 10 rand that I gave him.