Bad bad service at Festival mall Kempton park

I bought 4 tracksuits at Jam Cosmo mall and I was just passing by as I live at Boksburg only to find out at home that I was overcharged the cashier made a mistake and scaned 1 twice in the morning of Sunday 27th June I called the store and explain that even live far Nomalanga (Store man anger) asked for me to send the receipt so she can investigate and also check the footage and get back to me on the 30th of June to confirm yes it was the cashier's mistake I then asked her if it will be possible for me to get a refund this side as for me going to Cosmo mall is equivalent to the amount overcharged and she said yes you can go to your nearest Jam and explain to them should they want to confirm with me they can. I then went to Festival mall Kempton park Jam store, Mpumi (Store manager) shouted me how her stock will be short and how she cannot resolve other branche's mistake and didnt even let me explain the situations around the matter or even confirm with Cosmo mall Jam. She made me feel so small like I was just a ********** with her shouting at me