Terrible online experience from makro

Makro has been giving me terrible customer service for a few months now due to online purchases. I've order something in february and the item hasn't been delivered to me, upon making numerous calls etc makro told me that the item was delivered to me which isn't true. Again after calling around and pushing them to investigate, they find out that the item was delivered to a wrong address and was the mistake of the courier. Now since they know this they still don't want to respond to me about how I get my items or even a refund. I keep being told that they are investigating. What's to investigate when the courier time freight does acknowledge that it was a mistake on their side. Why do I have to still wait? Makro needs to sort me out and then sort out things with the courier, I can't keep waiting for then to investigate when they already know I didn't receive my items