Builders has still not refunded me for cancelled order

Hi! I placed an order of R2850 with Builders Warehouse on 23 November. I was informed on 7 December that the order will be cancelled because they are out of stock, and that, since I've paid via credit card, "You will be immediately refunded for your cancelled item(s) if paid by credit card or account". I am still waiting for the amount to be reflected on my credit card account. I've queried it with Builders, but all they did, was crediting my online Builders account with R2850. Well, what use is the money there? I want my money back as promised! When can I expect to be refunded?