Courier costs exorbitant and slack communication

I ordered a package from a US supplier. The courier UPS seems to use SA Post Office for deliveries within SA. The delivery arrived today but although I supp**** my contact number I didn't receive a phone call and the person ended up talking to all sorts of other people on the property and then went away again without making delivery. The biggest issue is that the goods being delivered are valued at ZAR 7500 and the Post Office wants to charge me ZAR3,978.94 to take delivery!!!! It's outrageous.