Pacific Screening provided a negative reference on...

Pacific Screening provided a negative reference on me to a potential landlord. Their agreement with the landlord precludes the landlord from providing with any information beyond Pacific Screening's phone number. Pacific Screening will only tell me that I owe a debt to a previous landlord and will not say anything more. They say it is a confidential landlord/tenant reference and will not provide me with any information whatsoever about it. They won't say where this debt originated, how much it is, or even how old it is. I cannot dispute or resolve the debt, if it is somehow valid (or cheap enough to pay off just to make the extortion/mistake go away quickly!). I cannot imagine how this information can be used to deny housing to me and then be kept secret from me under the Fair Credit Reporting Act.

Update:
When I pointed out their black-letter violation of fderal law in withholding information about me from me, they relented and told me which former landlord reported negative information about me. It turns out that they did not even speak to that landlord but rather to another SRO tenant of that house who trash-talked me and gave inaccurate and outdated information about me. Apparently, they didn't bother to verify with whom they spoke before issuing a report. I was told Pacific Screening would follow up and re-inquire on this issue but it has been several weeks and nothing has happened. Time for legal action?