Double charge No refund

On the 28th Nov i purchase some goods from checkers Raslouw my card was swiped and the cashier say with so much attitude that my transaction was declined i showed her proof from the text i received that this is not correct. She then called her manager Stanley who assured me this will be refunded tommrow and convinced me to swipe again. Its 2 weeks and i still have not received my refund. I have given them bank statements showing the double deductions, wrote emails called serval times still no response. I honestly think Stanley and his staff have a dont carr attitude. I have been doing all my shopping for the last 6 years in this store and i will now stop after this poor service. I honestly can't believe a manager for a large retail brand will ignore your emails calls etc. His service is so poor that he won't even apologies for the rude cashier or his incompetence. He is still looking for two weeks for 2 transactions with the same card number,amount,and time. Even thou he has proof from FNB showing the double transactions.