Discovery Bank returned debit order fee R100

Account no. *** ino R Shaik In an attempt to charge me a fee for returned debit order, the bank effected a transaction of R100 x 2 on my account dated 20/05/2024. I did contact the third party and requested for debit order to be changed to 31st- this was not effected. Now i am out of pocket as the bank unlaterally effected this fee which was R12, 50.