Incompetence and greed

I having been using the Netcare St Augustine's hospital in durban for a while now. Of late i have been very unhappy with their billing department. On my wife's last visit i got a statement from my medical aid that everything was paid for. Now Netcare is harassing me with SMS's and emails and also threatening me with attorneys about unpaid accounts (mind you over only R450 whereas they have billed my medical aid over R150 000 this year alone). But Discovery has clearly paid them all the money due.