Failure to process claims for the past four months

Medshield has processed a claim for which I paid cash SIX TIMES for the past FEW Months but it has been rejected every time although the claim is payable by Medshield under PMP. I have supp**** proof to their complaints department that the claim is payable under PMB. They reprocess the claim over & over again but fail to rectify their administration so that the claim gets paid. Very Unacceptable Service.