Non delivery of Makro item ordered online- Courier Guy poor service

I ordered an expensive product from Makro online,. My order was acknowledged on 28th January 2025, and delivery was promised on 31st January 2025. Both Makro and Courier Guy sent me messages to say that the item had been delivered, but I have not received anything. When I queried it with Courier Guy, they sent me a copy of a receipt signed by someone called Karabo. I do not know anyone called Karabo, and nor do any of my family. I have been reaching our to both Makro and Courier Guy to explain my situation, but I do not get any useful responses from either of them