Question about ChexSystems response to me........

Hi,
I asked ChekSystems to provide me with "proof" of what they are reporting.
For each account they simply typed in "ChekSystems has no debt infomormation available".

If they are REPORTING this as a ding against me and I request proof of the debt, isn't it their responsibility to provide me with the info I am requesting (proof of the debt to include all documents, etc).
Or can they just report what they want to report with no accountability to me?
They keep telling me to "contact the party involved to see if the debt is owed".
Again, if ChexSystems is REPORTING this damaging info, they should have info to back up what they are reporting, correct?

And does anyone know of a type of form letter I can send back to ChekSystems to let them know I will not accept their response of "they have no proof of each debt" and that THEY must provide me with info on what they are reporting to businesses?

Thank you.