Underwriting which is ambiguous and intransparent

I am disappointed at the lack of accuracy by the underwriting department. I joined the medical aid 01/05/2018 with no waiting period imposed coming from Topmed yet when I request to add my son to be added to the medical aid who has been on Gems since 2008 they impose a waiting period for 3 months failing to examine his membership certificate from gems which shows he is still covered until 30/06/2018. This is lack of competency as I logged a query and the response I received is ambigious and there is no direct way of communicating with the underwriting department. Too much conspiracy.