Nando's Benmore - bad service and no response to refund

On 10 December 2022 I place an online order (***) with the Nando's branch in Benmore shopping center. I used a voucher that I had to pay for part of the amount and the outstanding amount was paid using my credit card. When I got to the store they were being loadshedded and when I asked for my order I was told that the amount I paid by credit card was still outstanding. I tried to explain first to the cashier and then asked for manager. The manager Collen was very abrupt and rude and refused to give me my order saying that as the credit card amount did not reflect on his store system I would have to pay that amount and Nando's online would refund me that amount. I was late and annoyed so I paid, stating that if that was not the case I would want a written apology and a refund from him. When the following week I saw that I was still debited for the amount twice, I called the customer care line and they said they would get him to send an apology and refund me the amount. Collen did call to ask for my email address and sent me a badly worded letter of apology although I had asked for a hand written and signed one. No refund was done. After a few more weeks I called Nando's customer care again to raise the lack of refund and no written apology letter, i was told again they would reach out to Collen to remedy the situation. To date I have neither my hand written apology or refund.