Rea Vaya Bus Rapid Transit

My 12 year old and me get the bus from Protea Glen bus stop to Thokoza park.when we tap in from Protea Glen the ticket machine warns us that we have low balance, when we get to Thokoza park station I ask one of the staff member to let me go out to fill up both cards , to my surprise he refused and told me I have to tap out to go to the ticket office to fill it up, I had no choice because my 12year old is going to school at eldos and there are no ticket office there ,so I had to tap out in order to top up the cards and tap in again to continue the same trip ,I felt that was not fair because now I'm being charged double for one trip.Is this reyavaya policy to treat their costumers this way or the staff is making their own policies