BUS DRIVER TELLS PASSENGER TO WAIT FOR NEXT BUS

My son bought a ticket at Checkers Money Market on Thursday morning. His ticket clearly stated that departure from Bellville to Mossel Bay was at 18h15. The bus arrived on time but the driver had the audacity to tell my son that he was not going to Mossel Bay he had to wait for the next bus. He was rude and obnoxious. My son was scared and he had to wait for the next bus that arrived at 18h30. Again the bus driver said that he must wait for the next bus. At 19h00, the final bus arrived and again the driver said that the previous buses went to Mossel Bay and that his bus was full. I went mental. My son was far from home we bought a ticket and he was in a ***** area of Bellville. I told hm to get on that bus. The driver was nice enough to make place for him on the bus. What is the purpose of buying a ticket then the bus drivers telling you whatever they want to. The bus service is very quick to point out that if you are late then there are no refunds. I want an explanation from Translux why their drivers would think that this was acceptable. How many other people were this done to as well.