The accounts department is in shambles

Three months ago, my wife and I welcomed our first child, our daughter, into the world. Just two weeks after she was born we had to take her into the ER for some tests (a nightmare, but she is totally happy and healthy now). Some of the tests involved PathCare bloods. Because she was not yet registered on our medical aid, we had to pay out of pocket and then claim this money back. In the flood of medical expenses that follow having a baby and two ER visits, they sent urgent payment requests, pressuring us to take advantage of early payment, etc. We did, and then they billed the medical aid (twice), who paid (twice). These early bills were riddled with errors. Our baby went by three different names (in some cases being charged three times because of this), and there were spelling errors throughout. The entire procedure was billed twice, once as private, once as medical aid, with almost identical amounts. It took 5 attempts to get a bill without the spelling errors, but the bill still seems to have repeated expenses. I send emails but they don't provide any new information, just the same route responses. They send emails, SMS's, threatening legal action for the money we owe them (except in reality, it is possible they owe us, but impossible to be certain). I have requested detail, itemized bills to ensure we are not being double charged, but they have ignored my requests.

We have no power against these companies and I am so tired of being exploited for every last cent.