Automation failure

I'm very unhappy with my revolving facility, I set my debit order date for the 27th as my salary goes into my account on the 26th, because the 27th was on a Sunday, they debit my account on the 25th without my knowledge, its get rejected, and than goes through on the the 26th, but still I get an sms on the 29th stating my account in in arrears, and my account was blocked, I contacted FNB via secure chat and they stated that it will be lifted in 48 hrs, which is unacceptable, because there was no fault on my side at all, and the Advisor Thabisile was not helpful at all, and disconnected the chat without giving me a positive outcome, and this action will also affect my credit score. I dont see why we must be punished for Automation that went wrong