Arrogance and lacking costumer service

Last week on Black Friday, I brought shoes from Rage-Durban CBD while I was in the store I fitted the displayed shoe and the assistant went to the back and came back with the pair of shoes I payed for them then I left. When I got home I realised that they actually had an odd pair packed for me. The following day(Saturday) I went to the nearest branch(Rage kwamunyandu mall) to exchange the shoes. They refused to exchange the shoes they said I must go back to Rage in Durban CBD they are the ones responsible for the correction of that mistake. When I got home late Saturday I realised that Rage KwaMnyandu Mall sales person didn't put the slip back in box. Sunday morning I woke up and head straight to Rage at kwamunyandu to enquire about my slip I was their first customer that day and they said they don't know nothing about my slip. I was occupied all week since I'm writing exams I only found time to report back to Rage at the Durban CBD today, I explained my issue to one of the sales lady by the name of (Zah) and she was utterly rude towards me, she was screaming at me demanding me to take something above what I had brought because they won't refund me simple because I have lost my slip and if I so want my refund I must go and get my slip where I left it(Kwamnyandu branch). I went to get my elder sister who works around town. When she got to the store they looked as if they will assist me... but as soon as she left almost everyone was talking about me and saying all things, demanding me to take something else, shouting at me in front of the customers made me feel so inferior as if I was pinning them because the size of the shoes I had with me had already ran out of stock, that I felt like breaking down. I reside at umlazi and I had to travel to town just to hear people belittling and taking advantage of me because of a mistake that I was not at all liable for and made me seem illiterate because of their barbaric attitude towards me. They made me look like a fool in front of other customers. I then called my brother to come to town and assist me, when he arrives, sales lady by the name of Thandah called their call centre and she spoke to Portia who then authorised that I must go back to Rage KwaMnyandu Mall since they still have stock and do the exchange. I'm really not happy and so hurt the way both branches treated me.