Vehicle FInance

I recently had a car through Standard Bank Vehicle Finance ( Mid Novemember) and first installment was suppose to be on the 26 of december 2017 Which was holiday and fell through to 27 but there was no debit order on my FNB account.

Today i receive an sms saying my account is over due but there was no debit order on my account, let alone an alert that they did a debit and it didnt go through for whatever reason. i waited till the 7th for money to be debited.

I call the call centre and assisted by a lady and she told me they had incorrect account number and im wondering how did they capyture as i submitted bith salary slip and bank statement which has same correct acc number and now im forced to pay the money due on a certain date which i dont have and should rather the first installment be on the Coming month end.