SAA not refunding my legitimate cancellation of a flight.

I cancelled a ticket with SAA more than 3 weeks ago because the workshop I was going to Capetown for were paying for our flights. An employee of SAA by the name of Nani contacted me to give them the new ticket which I did. Up until today they have done nothing about my refund. The cancellation was beyond my control but the employee said they would come back to me which the never did.