Frustrating process! Tired of repeating story and sending documents

I am lodging a formal complaint against DHL regarding shipment of a personal item. DHL incorrectly declared the shipment under HS6204 as "New cotton apparel with a commercial value of EUR 250". This, as set out in previous correspondence and attached documentation is factually incorrect. The item in question is a handmade personal dress of South African origin made in 2005, owned and worn for the past 20years. It was taken to Germany many years ago, forgotten to pack in her suitcase on her recent travels to Germany and returned very kindly by her friend who arranged for it to be sent to South Africa for her to be reunited with her as unaccompanied personal effects here in JHB. The item was sent via my daughter so we could arrange to meet with and return the item to her as I work from home and she is a student so we would be able to take delivery of said item. Ownership of the item has not changed, and the item has no commercial value but has a personal value to us. I am extremely disappointed that it requires this much run around and waste of our personal and professional time to sort out a simple personal item return despite providing all required documentation. Today, in spite of all of the documentation and calls to customer services, there is now a request for an invoice for the item!! The dress was handmade 20years ago, we do not have an invoice for it nor should it be required as there has been no commercial transaction for this item to attract custom duties! This needs to be escalated to management for expediting, and feedback urgently!!!