I needed to do a cashback by buying airtime for R10 at pep4461

I needed to do a cashback by buying airtime for R10 at pep4461.their cashier was rude n told me that I can't buy R10 airtime I can only buy for R30..I was in the que for 20min n when I finally got to pay point I was told this.she said that's how it's done at every pepcell but I was helped at another pepcell