Pick 'n Pay Online mess

I placed an online order on November 25th, and later that day, in the afternoon, I received an email informing me that one of the products was out of stock. I immediately cancelled my online transaction (25th of Nov). PnP online confirmed the cancellation. I received a text message on December 9 letting me know that the order is on its way and that the money has been deducted from my account. This took place after I cancelled the order on November 25. I got in touch with the call center to cancel delivery and get a refund. I've made a ton of calls and sent a ton of mails, but I still haven't received my refund. (There is no after-sales support at all; the client is supposed to follow up.) Client get penalized for PnP incompetence. Why does processing a refund take 4 days? Will I get compensated for banking fees and lost interest?