Fnb charges

I paid toll gates last week Tuesday that amount to R94, and they were like R11, R58 etc and we know that less than R100 doesn't gv sms. Unfortunately for me the toll gates doesn't take money immediately from ur bank. After 4 days i didnt have enough money wen the toll gates debited and the precious fnb paid R94 for me then a realised i jave a negative amount in my fnb acc. I transferred from my other bank to fnb so my acc is in positive... To my surprise R94 was taken plus R150... This R150 is for interest that fnb paid R94 to the toll gates. I dnt remember signing a contract with fnb to pay my debts on my behalf if i dnt have money in my acc. I have been on the phone for more than 45min trying to speak to a consultant and aftr speaking to a voice machine that dropped my call once then called again and spended another 20min on hold without any consultant answering my calls. I would like fnb to reverse my R150 in2 my acc. I ask u never ever pay for my debits if i have no balance in my acc.. i will not be charged R150 for a debit of R94. I refuse... i urge everyone to always look at their bank statements this bank will rip u off... we are not safe at all. I was lucky to see this as i had transferred a small amount of money and the balance was too low thats how i picked up that i was charged R150 for R94