Over debiting_

Why debit my account before my pay day our agreement was for you to debit my account on the 25th no one explained to me that if the 25th falls on a saturday then u gonna debit a day before and if theres no money you gonna charge me R200+ so it means all da time if da 25th fall on a weekend m gonna have to give you the R200+ for free this is just a ******* I want my money back Asap or Il take you to ombudsman.You dont have the right to go into my account and over debit me as you please,your call centre agents are so rude its not even funny I must use my money and time calling you claiming my money that we never agreed on I dont owe you I want my money