durban - Pretoria NO! only to Midrand!!!!

How can you book a ticket from Durban via Volksrust to Pretoria. When you get to Johannesburg they tell you bus is not going to Pretoria because you are only 3 clients who need to go to Pretoria. You need to get of at Caltex Midrand the bus is going on Harare root from there. Now we need to arrange with the people who had to fetch my son from Pta to drive all the way to Midrand. That is en excusable, what about safety and extra cost driving all the way to Midrand. Please explain????