Overdrawn Home Loan Account by Standard Bank

Standard Bank has overdrawn my home loan, such that they owe me R 250.30. It is now necessary for me to write a letter requesting repayment of this amount. <br> <br> I find it absolutely ludicrous that they have the ability to place a debit order on my account and take out more than necessary without any letter and when I request repayment of the overdrawn amount I need to send a letter.<br> <br> The call centre was helpful but I think the letter is completely ridiculous. <br>