Bonitas not paying authorised claims

I have received all necessary authorisations for my treatment. However, Bonitas is not paying the provider. The provider is now sending me threatening letters and demanding funds from me. I have complained about this several times, but this is a constant problem with Bonitas. Bonitas does not pay out claims to providers, even if authorisation is received. And every time you phone the call centre, your claim gets resent for processing which does not happen nor payment. The claims department also cannot be reached by telephone, making claiming a nightmare that takes weeks to finalise.