Postnet delivery

I had a parcel posted from Postnet Grahamstownn on the 11th February till today (07/03/2021) I haven't received my parcel. Unfortunately for me it is a cellphone and they only declared it missing on 03/03/2021 and they **** to say that it has been returned to the shipper, in which it has not. I tracked my parcel and it says that the last time it was in Johannesburg operations facility and from there they don't know where my parcel disappeared to. I am very unhappy about their service because when they advertise they say they are reliable. Even from calling their head office, they were not helpful in anyway instead they had an attitude towards assisting me.