MBD ABSA INSUFFICIENT FUND

I want nedbank to please please tell me who authorised the MBD Absa insufficient fund now I was charged R 8.60 x 6 times which this thing is affecting my finance to be real and I am soo soo soooo disappointed in Nedbank for doing I didn’t expect this from a finance company that I trust with my finance this is really shocking to be real , they must resolve this as soon as possible and refund my money from the day they started doing this deductions I mean this is ***** I did not sign up for this , this is a very worse bank trust me 😡😡😡😡. I repeat please fix this ASAP .