Spar bellairs shopping center taking my money and no sense of urgency to refund me

I went to Spar bellairs, northriding on the 26th February to buy monthly groceries. The card machine declined as apparently the system was off line. I am now still waiting for my refund. I have been back to Spar every day since asking what is going on and when will I get my money refund back. I have supp**** my bank statements and all the information Spar requested. Still to this day I have not had one call or any feedback. My debit orders have now bounced and I am the one having to pay the returned debit order fees and my credit history is now affected because of Spar. In future I will not go back to Spar to do my monthly shopping due to this and how I have been treated