SAA horror

Was supposed to leave Jfk for Johannesburg at 11:00 am to arrive in Jhb after 8am. Flight was delayed and ended up leaving at 23:00 12 hrs later from JFK. I live and work in Cape Town and had booked a return flight from Cape Town to Johannesburg enroute to the US and was supposed to leave in the afternoon 1 August to Cape Town. We arrived only after 20:00 with the delay. Upon arriving my flight had obviously left me behind (loss of money) I had to book another flight for 2 August (loss of more money) and a work day lost as I won’t be able to make it to work on time. Upon arriving at OR Tambo I was told by a Darren/ Darrel that SAA couldn’t accommodate me as my flight to CPT was not booked with them so as far as they are concerned my final destination is Jhb. So what this guy was ultimately saying I must sleep at the airport after a 15 hr flight and the fact that it was not my doing that I landed at night and not in the morning.