Paying interest on money not owed

<p>I never use the budget facility on my credit card and every week or so I pay off all the debt on my credit card. I now discover that Checkers Sunnyside has accidently put R417.75 through on budget on 25 Aug, but I paid off the whole amount on 26 Aug. Although I don’t owe that amount, ABSA is still charging me 21% interest on it. I feel that it is very unfair. Checkers made the mistake, I got no advantage from it, but ABSA still makes me pay.</p> <p> </p>