Return of Item - Loch Logan Mall

For Christmas I bought a lovely Rose Gold necklace for my wife from the Loch Logan Mall American Swiss in Bloemfontein. To my disappointment, after wearing the necklace once, the connecting links opened and the locket separated from the necklace. I am not sure if this is a defective necklace, or just poor design, but either way, I decided to return the necklace today (30/12/2017) to rather buy a different one from HDL. The lady at the shop they took my details and said they would contact me when they have enough money to refund me. Is this common practice? Can somebody tell me why they coulded just put through a refund on the card machine I used to pay for the item, as I paid cash? Is there also anyway I can find out how long it will take for me to get my refund, because they were all too excited to make the sale, but somehow it seems the refund process may take a while!