Missing luggage

This company lost my luggage on the 15th of June 2024 and I've been following up since the 16th and they last response was that they are not responsible for the loss. The drivers were the ones responsible for the loss of my luggage because they're the ones who didn't check the tag and gave my luggage to the wrong person at a stop before Cape Town terminal, which was my destination. How is this not their fault but mine??? I want my bag Intercape!!