PACKAGE LOST BY POSTNET !!!

I sent a package at PostNet Durban in Glenwood on the 05th of April , to be delivered at PostNet Dobsonville Johannesburg . To my surprise the package can no longer be traced as per PostNet Glenwood. Is this the service that they offer to clients ? what do I do now when they do not know where the package is. I was assisted by Misherlene and have spoke to Kyle yet my case is still not resolved.