non payment to pathcare

I'm disappointed to get an outstanding balance of R 2000 for tests done by pathcare whilst my child was in hospital. Apparently these tests are not covered under bonitas and I have to pay the amount in two weeks from the notice date. I never gave approval for these tests nor was I aware that they don't cover it. I don't have any agreement with pathcare, why should I be held accountable for non payment from the medical and.I got authorisation for admission which should be enough