The Cross trainer at Rosebank Mall refusing to give me my refund after a transaction was performed twice

22 June 2021 I bought a tshirt at Cross Trainer Rosebank Mall. I do not know the workers name of which was helping me but the receipt was written Amanda..I paid with my card and it took time to process the transaction with the first speed point and it eventually Declined..She then tried the second speed point which was approved..When I got home..I went into my banking app and saw that the cross trainer transaction was performed twice...I then spoke to the nedbank consultant to verify that for me which he did and he told me that Nedbank can't reverse it for me i have to go to the store to reverse it..I called them on the 23rd and they had told me that they'd do a follow up and give me a call which they didn't..I had to call them to find out whereas they had made that mistake..I was told to come so we could fix this and as I am writing this I'm at Rosebank..I went and with my statement and they told me that they can't help me it is not their problem..I am not happy with their service and I would like to get my refund because I was treated unprofessionally and unfriendly..I was basically dismissed..their service towards their custom is disgusting..