FAILURE TO DELIVER ONLINE ORDER AND NOT REFUNDING

I placed an online order 16 days ago. Only one out of 3 items was delivered last week Wednesday. I have made several phone calls regarding the outstanding items and I've been promised someone will call me back which never happened. I told them to cancel and refund and I've now been told to wait another 21 days before they can start processing my refund. Makro doesn't have stock neither does the supplier. Why must I wait another 21 days when there's no stock?