I need my 10% back that Matlosana Mall solo shoes took from me

I layby a pair of white shoes from solo shoes last year at Potchefstroom Mooirivier and when I went there I saw a message that says the shop is closed so we can check our shoes at solo shoes,Matlosana Mall. I went to Matlosana Mall and told them that I need to paid up my shoes but I need to change them as I do not need the white colour now so they told me that it won’t be possible because the items are not loaded in their system yet, and I kept on checking them until last month they told me that the items are loaded when I went there to change the item they told me that they are going to take 10% from the amount that I have paid because the layby had expired and I told them that but it was not my fault as I have been checking on them regularly but there was nothing happening, so I had to let them to take the 10% from the money because it was long story and the manager said I need to pay that 10% and they showed me the message that when the layby has expired the 10% should be taken and I told them that I do not dispute that but my matter is not the same, so I need solo to pay back my money because I did not fault them they are the one who did not treat me well.