No Help From SAA & Rigid Policies

I purchased a ticket online from SAA Sunday the 26th of March and erroneously auto-filled the wrong surname for one of the passengers. I didn't pick it up until 10 minutes later when the confirmation email came in. I called the airline immediately and they said that their policy doesn't allow for a name/surname change. I then requested to cancel the ticket and get a refund and pay a cancellation fee, to which they told me my ticket type doesn't allow me to get a refund. I don't get how SAA doesn't allow for this grace period; I know other airlines have a 24-hour grace period. The customer service agents are not very helpful, they just told me I can't change names nor can I get a refund because of my ticket type.

I did some research and saw something that states that whatever ticket type one has, passengers, have the right to request a refund amount for airport taxes and fees. Why was this not stated in the calls that I've been making in the last 24 hours?

South African Airways is willing to take R7 600 for an error I made and picked up 10 minutes later and tried to call to rectify but they won't allow it. The SAA policy in place seems to be extremely rigid and unfair. This is a booking for a trip in May. Are you seriously saying I cannot change an error whatsoever??? Are you, as an airline saying that customers can never make mistakes or else, they forfeit their money?!