As for the DV request, was it timely, meaning was it sent within 30 days of their dunning notice (or without prior dunning notice)?
If not, it imposes no cease collection bar or other limitations, and can be ignored.
If the DV was not timely, I would not pursue any violations on thier part that is based only on a lack of what you consider adequate validation. There would be no violation unless/until they continue collection activities without first having provided adequate validation.
Even if timely, if you consider their response to not be adequate validatation, that per se is not a violation. There is no requirement to or period for sending debt validation under the FDCPA, so it you consider their response to not be adequate validation, it is the same as if they sent nothing. They would remain under a cease collection bar.
It appears, in view of the new information obtained, that either a dispute with the CRA or an identity theft block may now be the more appropriate step. You now have a factual issue and basis for contesting the entire debt by way of a dispute to the CRAs.
They may verify, notwithstanding any documentation or arguments you present with your dispute, but their verification then becomes basis for civil action on your part, which is your ultimate step in getting judicial review of the reasonableness of their investigation.
As an interim process, with or without any issues of debt collector verification via either a DV or dispute, if you file a police report and submit to the CRA, you can get the collection blocked from your credit report under the identity theft process of fcra 605B. That removes any scoring implications, but does not resolve the underlying issue of proving the legitimacy of the debt, so I would pursue both a dispute, opening the door for civil action on your part, and meanwhile get the collection removed from your credit report using the identity theft process.
