Unhappy customer

I booked a ticket from Johannesburg to Kimberley on the 22nd November 2017....and then I realized that I needed to cancel as I had to attend an urgent meeting the following day. When I called the Greyhound call center to cancel within 24hours the lady that was helping me promised to call me back later to finalize the cancellation. I waited in vain and she never called. Then 6 hours later I called back only to be told that there would be a 20 % penalty and I don’t qualify for a refund but will have to book another ticket within 6 months. This would be a problem for me because I hardly use a bus , therefore I need my money back. I would appreciate it if someone got back to me as soon as possible.