Pathetic customer service as i patiently await my refund....

On the 17th of April, i cancelled a ticket from Port Elizabeth to Cape Town. The terms and conditions on the ticket says refunds will be done WITHIN 15 days. Needless to say, it is now more than 15 days and I am still waiting. When you call, the manager is never available and the agents keep spinning a different line. i don't know who else to talk to because they cannot give me a number for someone higher than the manager. I am disgusted by this pathetic service