Where is my package?Bad Bad customer service! First & LAST time using DHL

This was my first time buying anything from overseas, and i thought the service will be quick , efficient and smooth, unfortunately it has been a tumultuous experience. The service that i got from Kekanetswe Ruele & Tebogo Ntlebi has been appalling. i was notified that my shipment has arrived and need to submit documents, i did do that,however upon investigation i found that the invoice was incorrect it had exorbitant charges, eventually after several emails,the invoice was rectified, and i made arrangements to pay on 24 May 2019. i thought my problems were over, and all i had to do was wait for consignment as someone even called me to verify my address, to my surprise and disappointment , i got slapped with another bill from Tebogo Ntlebi,, Now this email contains a letter of intent from CBCU at customs, requiring I pay R5000 (plus R600 fee to DHL, for what reason I don't know) its written an jargon , i cannot get hold of Tebogo Ntlebi whom i have called countless times and emailed in order for her to explain to me, but all my efforts were futile,i don't own a company, and this is for my pvt use. may you please intervene and help me resolve this matter.This is absolutely appalling service and an injustice and I beg that this be resolved.