TFG Online Taking Money and Not delivering the full order!

I ordered 2 items online from Totalsports under The Foschini Group (TFG) and I am extremely disappointed . They took my money for both items and now I just received an email from them telling me they only received payment for 1 item!! After they received my payment for both items I got an email from them thanking me for my payment and now they are telling me that they only received payment for one item and that they are cancelling my other order. When I spoke to one of their call centre agents last week they confirmed that payment was received for my items. When I called them now, they are telling me that they had a system problem which took more orders than what they had on stock. That is not my problem, I want both my items which I have already paid for! I have my bank statement to prove that. I am definitely reporting them.