early debit order?????

I have a debit order set up with Telkom for more than 6years already, its always been set up for the 25th of the month. In the past, when the 25th falls on a weekend Telkom will sms to inform me of the date they will debit my account. This month Telkom debited my account on the 23rd of the month, causing unpaid fees as I only get paid the 25th of the month. They debited my account again this morning 28/08/2018 and then immediately sent an sms to inform me that my account is in arrears and my line might be cut due to outstanding fees. PLEASE TELL ME WHY YOU INCONVENIENCED ME AND DEBITED MY ACCOUNT BEFORE THE TIME AND AFFECTED MY CREDIT RECORD? AND MY UNPAID FEES??? This happened to 4 of my colleagues as well. I am very unhappy about this issue and would like to be called and assisted with this issue! thank you!