Havn't read the last few pages (so not sure if completely relevant) but i ordered something through DHL recently and they had similar to me. Some notional charge on shipping that they dream up to calculate their own VAT because (they said) there was no shipping value declared on the item.
Messed me around for 2 days. Finally asked them about the exact provenance of this notional charge and if they could provide me with a SAD (the customs proof) and they said "oh it's an error". Seemed very fishy.
Dunno if it's similar to you but anyway.