ABSA did not debit my account as per agreement with R545 on the 26th of June for my loan

ABSA did not debit my account as per agreement with R545 on the 26th of June for my loan. Today I received a sms saying that I missed a payment. There has been money in my account since the 25th of June to date and now they want me to pay R700 for a error on their side.