Thank you for using our forum. My name is ***** ***** I hope to assist you today.
I am very sorry to learn of this situation.
Credit reporting is done on a time frame (so late payments made between 1 and 30 days late are reported in one block).
Unfortunately as your loan payment was made a day late, the creditor is within its rights to file a report with the credit reporting agencies for the late payment.
However, a single late payment should not have any long term impact on your credit (it may have an immediate impact, but this will be short term and your credit score should promptly rebound).
Furthermore, there is a difference between your "credit score" and your "credit worthiness" (what lenders and creditors look at when actually making lending decisions) - they actually read those reports and will see that there may be a late payment, but it was made, and there was only one, again, a single late payment is not a significant issue.
I am surprised that your creditor will not work with you on a single late payment made one day late. Most creditors will. You may want to look into refinancing your loan with another creditor (try local banks or credit unions). You can usually get better customer service and much better terms than a creditor that is unwilling to work with you under the circumstances you describe.