Exorbitant on-counter-service fees

I visited the institution on the 2nd April 2025, to pay my mortgage bond installment. I also wanted to enquire about the on-counter-service-fee. I was extremely shocked and frustrated about the money that I've lost to the company. The reason is I'm computer savvy and not utilizing that skill because of lack of information and advice from the bank just got me hot under the collar. I had thought when I pay/deposit my mortgage installment is for free, but I was confronted with the surprise of my life with the exorbitant on-counter-service-fees. Which, I was told by the teller that it's R90.00 and R4.00 for every R100. Had the bank adviced me appropriately, after picking up that I'm paying my installment on the counter and explained the options available to me, I could have signed a debit order or did EFT, and could have saved a lot money that have gone to reduce my balance and or interest. I've been paying this account for the past 19 years and I'm almost nearing settling my mortgage. I then called the home Loan department and I was told/adviced to take it up with the branch manager, which i don't expect much other than apology.I'm going to do on my next visit of payment. I couldn't do it immediately because I had to dash somewhere else. And I know that a lot of customers who are semi literate and literate are not aware of this exorbitant service fees.