Bad customer service

On the 25th April, i went to pep at park station around 15:00 to 16:00. I was assisted by a lady didn't even get her name because she didn't have her name tag. Went there to buy blue tooth earphones, the lady gave me a perthic and a very bad service i have never felt that small and humilated. The lady that assisted me instead of telling me that the earphones i am looking for are out of stock, she kept saying upstairs and it was confusing to me what did she mean. I decided to withdraw R100 at the till and she told me i must buy something before i male the withdrawal, i decided to buy R12 airtime. The stupid lady from pep assumed that i wanted vodacom and she didn't even ask me which network i want to buy. Then i told her no i don't want vodacom because i am using telkom, she said to me R12 is only voda with a stinking attitude. Told her that how the hell i'm supposed to know that only voda is selling R12 airtime i am not selling aitimes to know that information. Hell broke loose she told me that i must apologise because i was wrong ***, she kept on shouting at me and what ****ed me off most her supervisor was next to her and she kept on telling her to shut her mouth but no the lady had too much energy. I even decided to leave the store because i was disrespected and insulted by a cashier. Or maybe that is how pep staff is trained to humulate their customers and make them look stupid infront of other customers. And i want a written apology and why did she act the way she did.