600% INCREASE IN TRANSACTION COST?????

I am managing my mentally disabled sisters bank account. Only her monthly pension is paid into this account and immediately transferred to my account. Besides the montly service fee of R12-00, there used to be a transaction fee of R1-00 for thr one payment. Last month this amount increased to R7, thus being increased by 600%. I find it unacceptable that disabled people are charged 600% more on one single transaction!