Struggling to get refund

On the 9th of December I bought at Makro and I was double charged, to this date I am still struggling to get my refund. What worries me the most is the way Makro is responding to this situation they are telling me about standard bank, what do I have to do with standard bank because at made a purchase at Macro not standard? this is their internal problem they should just give me back my money and sort their problems with standard bank without including me.