Parcel stuck in SA....please help.

I have been waiting since 18 May 2018 for a package that my sister in law sent to us in NZ....it is now 3 months and it doesn't look like it has even left SA yet. The website never works for one and when you do find other websites to track it, it seems that it has gone all over the country from Pretoria to Joburg to PE and is now stuck at Durmail. I have emailed customer services, but they don't even bother replying. What else can I do??