Courier guy lost my parcel but they are not taking responsibility

I ordered new car keys and transponder chip from motokey and paid R140 for over the night. After three days i receive courier guy track number. Since 5 August 2024 i didnt receive my parcel i call them and there is no solution for my parcel and it is no where to be found. On track it shows that the parcel is at Joburg but they cant find it. I need my parcel or the courier guy to buy the other one for me. I am fighting with my customers for the key now. Please i need my parcel i keep on calling but no help