unpaid bill for hospitalisation for 2013

Its been two months now that I complained about the unpaid bill and now I was send an sms by to say I must come and settle the account which it increased from R6464.27 to R6820.55 . I called the medical aid this morning and they gave me *** spoke to Valencia and she said she is going to report it to her .2013 November was admitted at hospital at ICU and before I was at casualty preparing me for admission and the hospital got authorization (***)from the medical aid to go ahead . Since then the bills were not paid and I was called by the hospital to say where is their money , the amount that is needed is R 6464.27 . I did call the medical aid and they gave me lots of references and said they will investigate , later on I met with their consultants and told me that a report was written and they will pay the outstanding amount but it took time until I consulted Nthabiseng Ndini she said she will assist . Friday 24 2015 the hospital called me to find out when is the payment being done . I send Nthabiseng a whatapp to find out from her the feedback from the medical aid and she rep**** saying the wont pay . Need your help with this problem . Regards Priscilla Modisakeng