Rude cashier and I felt disrespected

I went to do a size exchange and had a slip. There was no security at door then just went in with item inside plastic then took the correct size to exchange at till. Cashier by name phindile shouted at me saying why did I come inside the store. I responded not all pep stores have security at door how would I have known, then she kept on shouting at me like I'm a primary school kid. I asked for a manager only to find out she was exactly next to us at till's however she was quiet and never intervened even when I asked her if what the cashier is doing is customer centric. The managers name is Zamokuhle. Store name is pep ndofaya mall. My contact number is ***. Email is ***