Netcare waterfall review: severe negligence

I left the country in March and booked my dad an appointment with a neurologist at netcare waterfall because he still had symptoms of a minor stroke he had a few years back. He could function very well and did not need any assistance whatsoever getting around. Long story short He went on for a sleep apnea and strangely ended up in ICU for 6 weeks for an undisclosed "infection" and almost 1/4 million rand bill. I came back last week to find that He is soley dependant on people at home to do anything and everything. I am so livid and to think that I contacted them earlier this year and they gave me a lousy response.
I want answers because the only obvious thing to do now is sue and I'm not threatening I'm guaranteeing.