Inconvenience as transaction went through twice

We went to the Woodmead store this Sat to pay a deposit for our dinning set, the lady charged me twice on my card. After a good few hours, they told me the only option was to cancel it, and they cannot guarantee I will get my money tomorrow. This was such an inconvenience, as two accounts of R5000, went off my card, and I'm sitting on an overdraft. Who will compensate me for my fees? They showed no remOrse or empathy whatsoever! It felt like they didn't even care for my sale. This is so wrong. What would have happened if the entire amount of the set I bought sent through twice!!!! The lady just stood there with no response, whilst the manger liases with me. How would she feel if this happened to her.....instead of the manager asking her why she put it though twice, he's asking me, which I felt is wrong! I really love the set but had no other option but to cancel my order. I feel so disappointed!