FEDHEALTH APPROVED MY HOSPITAL AUTHORIZATION BUT PAID NOTHING

I am 20 weeks pregnant, i went to ER at Cape Cage because i had some pains and i was spotting. The following day i called Fedhealth for authorization since i was at Emergency and the authorization was approved. Yesterday i got my statement for Fedhealth and they didnt want to pay my claim reasons unknown. I called their call centre wanted to find out why is my claim still not paid whereas i had the auth as required and the call centre agent said she doesnt know why. Now Cape Gate Mediclinic is sending me demand letters threatening to hand my account over. Why is Fedhealth not paying hospital claims even if you have an auth as they require.