Credit reporting agencies unfortunately, use information provided primarily by your vendors. Sometimes all it takes is one missed or disputed invoice and the reporting agency lists you as a "slow payer", especially if the total volume of their information on you is small. To help balance their information, it is a good practice to provide them with your payables (including contact names and numbers) so they have verifyable information of your payment history. As appealing as "legal action" might seem, I believe it would be a long and difficult process. Keep in mind, they do not make up or fabricate information, they just employ information that could be out dated, factually incorrect or otherwise flawed.