Refusing to Refund my money

I trust you are well. On the 30th of August I made a payment to Shein for purchases ordered on their App. I made a payment of R565 using an EFT payment option provided by shein on their app. After 2 days I get an email saying my order was canceled due to non payment. I have submitted proof of payment to Shein but they refuse to Refund my money or process my order. Please advise what I need to do order to get my money back. I have attached proof of payment as well as proof of transaction from my bank.

Hoping to hear from you soon.

Kind regards Thembisa Ndlovu *** ***