Extra charges

I would love help to understand something. I bought items at Shein online and it said I would recieve free shipping if I order at the amount more than R1,050.00 and my order was R1,195. I have been expecting the clothes from the 17-22 May 2021 but as per tracking history from Shein my parcel was here at jhb from 23 April 2021 , it sat for weeks there until I decided to call Aramex , when I called I was told it's in customs waiting for clearance. I called almost every 2nd day after I responded to the email that asked me me to send documentation to prove that I have purchased the items ,I did and time went by with my parcel still held at customs . After I called yesterday I recieved an email with an invoice of what I need to pay for vat, customs, penalty but all in all I am expected to pay R1660.51 to Aramex for my order that costs me R1195 at Shein.