Bad service

No one told me about customs now I'm requested to pay +R760 after I spent +R3100 on my order. I request for a refund it's taking long to be processed. Some company called Buffalo keeps contacting me with regards to my order and they say if I don't pay they will destroy my package meaning it will never get back to Shein and for Shein to refund they need to receive the package. Like *** is all this bull****. What's free delivery on the shein website? Why are they not transparent with their shipping costs??