Gautrain complaint

Hatfield Station. I had 5 minutes to get to the train and took the lift down. When I got to the platform there were still 3 minutes left. I approached the door with 3 minutes to go and the train just left the station without waiting the 3 scheduled minutes. Therefore, I had to wait another 25 minutes before I could leave the station. Since when are train drivers allowed their own time schedule? Surely thus is not safe. Utterly disgusted with their lack of proper service.