R5600 penalty fee charged to me due to blatant incompetence/*******ion on DHL's part

Where do I even start. The amount of incompetence shown in my dealings with DHL in the last two months is staggering. My parcel was pulled by CBCU at OR Tambo for value verification. No worries - all my documentation is in order and the parcel value is honestly declared and everything. I submitted all of the required proof of value documents (on January 30, 12:40pm) to Kekanetswe Ruele just 21 hours after being informed about the CBCU stop (on January 29, 15:03). I repeatedly called and emailed her to attempt to contact her and ensure that progress was being made. Not once did she answer my phone calls or emails until I received an email on 12 February with the invoice for customs duties and VAT payable on the order, after which I was told clearance would be processed. I paid and sent her the proof at 9:59am on 15 February. I was then told that the proof was received and she was waiting for finance dept. to allocate funds to them to process release of the parcel. A week went by with no news, and I started to attempt calling her daily. Not on one single occasion did she answer my call. Eventually, I received an email from her on 2 March 10:04am. Recall that I submitted my proof documents to her 5 business hours after being asked to. Now this email contains a letter of intent from CBCU at customs, requiring I pay R5000 (plus R600 fee to DHL, for what reason I don't know) penalty, for the sole reason of: MY DOCUMENTS NOT BEING SUBMITTED WITHIN 14 DAYS. No issues with value of parcel declared or anything. This is absolutely appalling service and an injustice and I beg that this be resolved. I shall not be paying a fine for DHL's incredible incompetence, bordering on *******ion. I have all the proof required to back up this complaint, in form of written email correspondence.