Worst place to order from

I ordered Burger King and added a promo to get R100 off. I paid with my card and then got charged the full amount excluding my promo.

If i hadnt check the charge i wouldve never known they over charged me. Im now being told to wait 3-10 business days for my refund, and I feel it was not my fault that this happened as the company should reimburse the full balance of the order if i am to wait for 3-10 business days. If they arent willing to reimburse the full amount then they ahould make a plan to get this paid immediately.