Worst experience with DHL

I ordered hair from Nigeria 3 weeks ago and I was shipped through DHL as usual. I was sent an invoice for the an amount of R692,00 to be paid and the tracking number said I will receive my package on the 3rd of May. On Monday I called them they told me my package has been randomly selected by port health because so that they could test the hair serum. How does Port health randomly select shipment and detain it without communication. I asked them why they never told me this prior to sending me the date of delivery and before paying the invoice they told me we are sorry mam there is nothing we can do. They put me through to 10 different extensions and keep telling me we will call you back. I have lost thousands from this delay when all they could have done is told me is communicated with me before instead of telling me after I paid for shipment. Port health will make you guys lose so much money and I personally will never ever ship anything through DHL they are the worst shipping method to use!!!!!