Problem with a company's investigation into an existing problem: Credit reporting or other personal consumer reports

The late payment reported on this account is inaccurate and does not reflect my actual payment history. I believe this information has been reported in error, and I am requesting a thorough investigation into the accuracy of the reported delinquency. If the furnisher can not provide complete and verifiable documentation supporting the reported late payment, this inaccurate information should be corrected or removed from my credit report.