No one's problem if your parcel is ******!!!

We couriered a Cellphone From Pretoria to Durban in June 2020. After three days we followed up on the parcel as they said it takes 3 -5 days. The parcel was still in JHB. After a week we tracked it again and it was still in JHB. After a while we were notified by the Postnet Branch that the parcel is missing... We followed up and asked so whats the next step as it cant just be missing. Ever since we as the customer have received no help at all with regards to a solution. They asked us for the IMEI number on the phone which we do not have as it was couriered it its original box. Because we cant provide that IMEI number all of a sudden they do not cover electronics.... This was never mentioned to us or even not even asked for insurance on the package.. Now we are sitting with a loss and no one seems to want to take responsibility. We place our goods in their hands and I just need to accept its gone??? HOW DOES THIS WORK????? We even called head office and its been a month with no feedback at all. I will never ever ever trust them again and I am taking this matter further!