Unpaid hospital bill

I have a medical aid with sizwe my problem is I had bloods done in hospital I was admitted medical aid paid only half of the bill now I have lancet on my case about a bill that a medical aid did not pay, I'm on affordable plan with sizwe and they said they pay every thing for in hospital patients, I called sizwe so many times to sort out this problem even today it's not sorted I'm so tired of calling them cause I keep getting the same response which is they will sort it out its going for a year now I don't what to do anymore.