Non payment for Network listed GP

I have submitted a claim which I paid for cash and need reimbursed for a network listed GP who practises out of a general facility who bills all consultations under the managing Dr & Associates. Fedhealth refuses to refund me as Dr Sauer hasn't billed me directly. Scripts filled the same day were issued by Dr Sauer and yet medical aid still refuses to refund me - their reasons \Dr Sauer is contracted to us