POOR SERVICE FROM DHL

I have a shipment that is been with OR Tambo since last week 27 March 2018, have paid DHL on the 28 of March 2018 as freight fowarders for my shipment and i have been receiving an extremely poor service from them, i am calling them all the time for an update and would be kept on hold for a long time from one agent to the other, they hardly respond to emails and their agents are not always up to date with the status of the shipment with customs, different agent will give a different update in one day, they do not ask for documentation from their clients ahead of SARS Customs as they are not doing this for the first time and should know the documents that will be required for clearance processes, the shipment is still not cleared with SARS due to delayed communication to me, yesterday when i called them for the third time, only then i got to know that there is another document required by Customs, had i not called them and forced them to send me an email requesting the document, they would have not communicated this to me.