No reponse to queries

We recently sent a package to the USA, it was held up and customs and later returned to SA. The reason for the package being sent back was that DHL put their labels over our shipping labels, that clearly stated do not cover. We would like to be refunded for the shipment that was not delivered due to fault of DHL. Waybill number is provided in the acc/policy number textbox. I've logged 2 calls with DHL but none have been rep**** to.