Lost parcel

I placed an online order which amounted to R1500 on the 25th of June. Surprisingly I got a message that my parcel has been delivered on the 27th of June but I did not receive it. I have tried to call the call centre so many times and being told that the parcel was signed off by someone I don’t even know. I’ve been told my query has been escalated and they will get back to me within 24 to 48 hours but no one is keeping in touch with me. At this point I just want them to refund me and we go our separate ways since they know nothing about customer service . Why am i even the one to call them begging for an update for a mistake that was clearly not mine