Medically held-open ticket costs more to use than a NEW ticket

I have a so-called held-open flight due to being admitted to hospital in Jan 2022. I had to cancel and was informed by email that the flight would be held over for more than a year. When 10 months later I wanted to use that flight, the extra cost turned out to be more than a NEW booking. So goodbye Flight Centre and Airlink. Never again. My advice - don't book through agents. Avoid Airlink. I had to forfeit my held-open flight and bought a flight the SAfair. SAfair would not discuss the matter with me, saying I could only communicate through Flight Centre.