Refund for a bus fair

Booked a greyhound ticket on the 19th for a 21st June trip.cancelled on the 20th,due to unforeseeable circumstances I decided against travelling.now I went to greyhound to cancel the whole thing(ticket)asking for a refund of R410.the salesperson said I can't get it what will happen rather is they will pass it on the next trip.meaning next time I won't buy a ticket I will just have to remind them that I still have a pending ticket of which I didn't get a refund for.first of all,I don't see myself travelling anytime soon.secondly I want their position with regard to refunds cos in sure this is not an isolated incident.all I want is my refund!!!! And your staff must know how to explain and the must have a good customer services