Pathetic and useless and heartless airline

Not willing to assist me as a sick client who urgently booked a flight and not willing to assist me with a wheelchair I have cellulitis on my foot and unable to walk to the flight at all this booking came up as a matter of life and death and fly safair refused to accommodate me with a wheel chair and the only option they can offer is that I need to change the flight or I should walk to the flight and this needs to be sorted out 48 hours prior to the flight How do I make this arrangements 48 hours prior to the flight if the flight was only booked 2 hours ago pathetic and ******* call centre staff portia and her team leader