Disappointed by wfs

On march 2018 Woolworths fail to debit money on my account, their reason when I receive their call is that on Friday was a holiday they couldn't debit ,I ask them it was not months end ,Saturday was month my agreement with them was last day of the month not when it suits them,the lady ask me to go an make a payment in the store for about R700.00 which I refused and agree to pay maximum of my instalment, I paid 400 and my installment was 365,still I received a call thanking me for payment as they won't be able to debit until I pay what they request, I refused again and told a lady that I will pay myself at store as they failed me,and I am doing that, now I received an SMS being informed about a profile is been send to credit bureau, for what reason?I don't get paid twice a month only once, so I can't make a double payment.