Disappointed in Greyhound bus services

I took a bus on Saturday from Cape Town to Bloemfontein. The bus broke down an hour after Touwsriver. We had to wait for 4hours for a mechanic to come out of Cape Town to fix the bus. The first mechanic couldn't find the problem so we had to wait another 2 hours for another mechanic. This is very frustrating for a bus like greyhound we don't expect things like this to happen. It's very unprofessional. I would like to be refunded for the service that I received.