Unprofessional behavior

On Friday 6June 2025,I went to Cash crusaders in East London to buy cable for speakers but I was informed by the guy who advised me to buy it that i have bought an incorrect one. I couldn't go on Saturday due to other urgent matters. On Friday 13 June 2025 when I went for an exchange fortunately I was served by a lad by the name of Luthando whom later I was informed that he is a manager there, he asked me why did I keep for so long. Then I explained the reason, he said 7 days have lapsed. When I explained that today is 7th day he changed to say cables have no warranty. I told him that I didn't know that it was never explained to me. Wow!!! It was a long long argument of back and forth. He eventually left us and attended to another customer whilst we were still talking, then he called a junior staff to attend to us. The young lad was very unprofessional with no customer etiquette at all. The exchange would cost us more money instead we didn't understand the whole fuss.