MARINANHILL TOLL PLAZA OVERCHARGE

I'm so annoyed and disgusted at a potential new ****. My husband and I are travelling to PMB from Durban and when we get to the toll he taps our FNB card and then also requests the slip. The slip correctly reflects an amount of R16.50 but as I'm passing Hammarsdale I look at notification and R57 has been charged off our account. Obviously we didn't notice since we tapped but from now on I'm carrying cash. Already petrol is so high, now this is either a new money making syndicate or a genuine error by a tired colleague. Either way, going forward I'm not taking chances because I'm broke too!!!!