RUDE SUPERVISOR

I went to pick 'n pay(Thaba Mall) to exchange the packet of sweets that were bought by my colleague and its not the brand and type i wanted. After showing the security guard at the entrance, he directed me to the kiosk to do an exchange there. I found a cashier and she told me to wait for the supervisor and explain to her. The supervisor came and i asked her if i can change the packet for the ones i wanted? She asked me when did i buy them? I told her earlier on. She said to me "HOW CAN YOU BUY THIS THING AND RETURN THEM THE SAME DAY? I told her that as I sent my colleague and she rep****"YOU GUYS ARE A NUISANCE". I said to her but i explained to you that my colleague bought the wrong ones, i asked if I can go get the brand i wanted? She kept quiet and told the cashier to proceed, without any word they gave me my money.

I was angry because of the way she spoke to me and how she said we are a nuisance(i don't know who is we). I kindly ask that you train her on how to treat a customer. I am just not sure if I will ever shop there again with the kind of service I got today.