DHL service

I have received 3 shipments from international suppliers who used DHL / Express (I have told them not to do so in the future). I have sent at least SIX emails over as many weeks requesting TAX INVOICES for shipmentds I have PAID FOR though your on-line e-commerce platform and to plesae give me a CERDIT APPLICATION. I have ALL the mails, your staff just IGNORE them. Perhaps I should publish their names ? Someone please call me