Frustration over the handling of my account by a Sun International Sales and Contracts Adminstrator

My Vacation Club membership has been locked as I refuse to pay the R150 penalty that has been charged to my account on the basis that the annual levy was not paid timeously, I have repeatedly told the administrator that I cannot pay an invoice timeously if it was not received, and invoices sent via email cannot be proved to be received, therefore I should be given the benefit of the doubt. I have now asked for this matter to be referred to management and have yet to have this happen. Or for the paltry sum of R150. You would think an organisation such as Sun International would train their administrators better to ensure their customer interactions are handled with professionalism and better judgment, especially as I have paid the levy, and I pay it annually. Beyond irritated!