Netcare Krugersdorp is a ****

I had a procedure at Netcare Krugersdorp and everything went well. I was only surprised when they call me that I'm owing them +R5000. I contacted my medical aid and they said they do pay for what was billed but the hospital incorrectly billed. The billing department doesn't want to assist they are only threatening me that they will commence with a debt collection procedure. This is a ****.