Appeal to get my parcel released and delivered - DHL Express SA

I am still waiting to receive my parcel since June 2020. I purchase items online and paid the customs and courier fees as part of the total cost. I then received a DHL waybill and the same to track my parcel. I was to receive my parcel in June 2020, but after several weeks, DHL responded to say that the delay was due to covid and the parcel was queued for customs inspection.

However, further weeks down the line, DHL is now requesting me to fill-in forms and pay customs penalties etc. for a shipment that was done by the online store and accepted by DHL.

I have used DHL to courier parcels and I filled in all details and pay charges before DHL accepts and couriers the parcel. So, obvious, the online store did the same before DHL accepted to ship the parcel.

So why am I being held responsible and being charged? How and why did DHL accept and shipped the parcel from the online store without the correct documentation? why am i the one to foot the bills when payment was done by the online store that shipped the goods?

How do I appeal this unfair and error by DHL?