Annoyed

I buy a weekly product from Hatfield to rosebank, I loaded extra money and for on at Hatfield to Centurion and it used my weekly product so I paid R75 instead of R31 for a trip to Centurion because of a glitch on your system that uses a trip if it's from starting point to a station before your ending point. I am highly unamused but this nonsense, nowhere is this explained should it not work like a 2 way trip and if you go anywhere else the credit on the card is used?? Please fix this you are robbing your customers now Monday I'll have to pay R81 getting home