Charging R10 additional per toll fee transaction when using garagecard

Starting the 1st of June, for some or other strange reason, standard bank decided that the R40 toll fees charged at the Cullinan The Rose toll gate is not enough - a R10 additional fee was charged each time I used my Gold card to pay for the tollgate. A total of R70 was charged during June to use the toll gate 7 times, and a total of R60 was charged to use the tollgate 6 times during July. The total banking fees in July for using the garage card only for toll gates and 1 time for petrol, results in R180 for the month. I did complain about the additional charges for the toll gate. standard bank did respond and said that it is a mistake, and will be rectified. The total of R130 that was charged additionally for using the garage card for the toll gate resulted in only R20 refund. I fail to understand the maths here!