DHL DOESNT NOT READ EMAILS AND RESPOND ON TIME

I had purchased an item from Turkey and unfortunately for me the Sender used DHL for their airfreight. I received customs documents from DHL, after viewing it I rep**** 2 hours later advising that there was an issue and something was incorrect. 2 days later and they were still not able to respond to my query. I called them and had been informed, it would cost me R950 to have the information amended, however I didnt authorize for the information to be submitted and I advised them before submission to get this corrected. The cargo has already arrived, so I had to pay an incorrect amount to get release of the cargo before it incurred additional costs- whilst still waiting for a supervisor to contact me. I really hope they correct the error on their side and refund me that which is due to me. DHL really need to work on their service and response times when dealing with customers - there should be no excuse to not action something if the information was provided within time.