The Reliable Online Store in Roodepoort is NOT reliable

I have ordered and paid for a product but I chaged my mind and informed them to cancel the order. They requested a bank confirmation letter to verify the account to wich the refund must be paid. That was the only possitive feedback from Reliable Store in Constantia Roodepoort. For five months now I am begging them for a refund but I don't get my money. What else can I do because I cannot handle it if I am ignored? Can I lay a claim of *****/theft agains them?