Was treated like a child in public

I bought R500 worth of products by them. I paid cash R200 and the remaining amount I swiped. They swiped my card and then on their side it shows declined. They tried twice and then it went through.I called this manager and she had a sort of laugh when I told her what happened as they took double my money.I then called the other manager Ken prinsloo who treaded me so badly in store like I was a ********.their customer service was very bad.