Never trust these guys

I booked a flight in January to visit my mother on her birthday in April. My mother fell ill and is now in Pretoria. I can't fly down to Port Elizabeth now. I spoke to the travel agent and the airline. Both of them refuse to refund me for cancelling a flight three weeks before the flight. I can understand if I am giving them an unreasonably short time to resell my ticket, but surely 3 weeks is enough time!? I never received any communication from them saying that the flight was non-refundable. Not on any communication was this printed. How can this be considered a reasonable or ethical business practise? When I asked why I had never received communication in this regard, the answer was that this complaint would be escalated to management. They billed this process as convenient and fast. The only thing that was fast about this process is how quickly they billed me.