Terrible customer service

I bought an item at the Edgars in mall of africa and I paid with my bank card. There was something wrong with their machines. Payment was processed from my side but apparently the transaction did not go through. I was told that even though they payment went through from my bank that it "MIGHT" reverse they are not sure. i I must wait a day to see whether or not the payment went through.. I had to pay for the item again. The Store manager Willem Manewyk was very rude to me. He didn't want to hear me out. He just dismissed my complaints about me being disadvantaged in this whole situation as I had to pay twice. The fault is on their side but I am the one who is disadvantaged.