Capitec Bank useless

I made a purchase at Dischem yesterday for over R800. The first time it declined. The second time it went through. Only after leaving did I notice that both transactions had been taken off my account. Now I've been phoning Capitec and Dischem numerous times to have the second amount reversed. Why should I have to run around and try get my money back..? Surely it is Capitec's job to have my money returned. Is that not the service we are paying for..? When this has happened with any other bank the money is reversed within a few minutes. Makes me wonder if my money is actually safe with Capitec...!