Horrible, horrible, horrible!!! Absolute nightmare!!!!

Worst courier service ever!!! I ordered 2 items from Amazon on the same day. The first was delivered a weeks ago with Aramex with no hiccups at all. No unexpected costs and no struggle. The second, to my horrible luck, was sent by UPS and is still being held by them (3 weeks after ordering). UPS is refusing to deliver my package before I pay their fees...for the third time. I have already paid shipping costs of R694, after that I received a ridiculous customs bill of another R739.50. At this stage, I have paid double the amount of my orders worth. I assumed this was the end of it and I would be receiving my parcel any day now, but yet again, I received a THIRD invoice for R345. It does not even state what the R345 is for. They are now refusing to ship my order any further than Kempton Park and it is being held there in a warehouse for who knows what reason. I have tried contacting every single email address and every single contact number that I could find without getting through to an actual human to talk to. This is getting ridiculous! At the bottom of the last invoice it states "Final assessment will be done to determine final charges". What does that even mean?? They know exactly how big the parcel is, how much it weighs and where it is going to. What assessment can there possibly be to determine more costs? I honestly don't even know what to do further. I am not going to pay 3 times for a single item.