who will pay for extra days

I took a loan from them now the repayment date has passed their money is been in my account long before repayment date I called them twice to address the issue since the debit order didn't go through on the promised date they told me not to panic until is 3 day who'll pay for extra days and what is the reason for the delay because it usually goes off every morning of the promised date and I would also like to know how can the reduce trust ratings while you never had any difficulties paying your loan I understand they need to look on your affordability but doesn't being a good payer count to them based on previous loans you have taken and never failed to pay back