FlySafair changes flight from evening to afternoon

On October 25th we purchased a return ticket Lanseria- Cape Town, purchased well in advance to get the special rate. Depart Lanseria morning of 9th February, return evening of 11th departing CT 19h30. Yesterday 7th January we were informed by Safair that the flight had been moved to 16:30. This makes an evening flight into an afternoon flight which means business activities booked for the afternoon of the 11th are not possible. I have conversed with Safair and their continued response is that this is within their rights, they have an operational problem (a month ahead?) and that they are prepared to refund the flight amount or put the passenger on the next flight - which is the next day - IF there is space. So the passenger is now out of pocket. At this stage, to get another evening flight CT to Lanseria on another carrier will cost an extra R350. To take the Safair Lanseria flight the next morning (if there is even a seat available) will incur hotel costs as well as problems with work arrangements the following day. Over repeated suggestions that this is hardly acceptable Safair just keeps saying they are within their rights. In no country, on no carrier, is it even remotely acceptable to change the whole time frame of a flight and not accommodate all of the passenger's resultant expenses. Business people in particular cannot operate under such conditions that a carrier can make such a major change to a flight time. The flight in question is FA304 on the 11th of February.