Debt validation/c & d

Call them, give them the 'case' number and then get their basic information. The fact they even have a 'case' number means they are likely an unlawful debt collector. Tell them up front you will not discuss the debt at all, that you just want the info. Also tell them that now you have spoken, they have 5 days to send you a dunning letter.

If they refuse to give you any info, then just remind them to send you the letter as mandated by law and then wait for it to come (if it ever does). Also remind them that since they now know how to contact you, it is unlawful for them to contact anyone at all....the ONLY reason they can contact a third party is to locate you, since they know where you are ( you can go ahead and give them your addy to make sure it is correct so they can send the letter), they no longer have a lawful reason to contact anyone else and inform them if they do so, you and those contacted will be forced to report them and possibly sue them for violations.