I just got a dunning letter from a Law Firm in Colorado (MJ Hecker & ASSociates) who claim they purchased a debt from an OC. These accounts are NOT listed on any of my credit reports yet. This is the first I have heard of this debt.
Which HIPAA letters do I need to send, and to whom? Do I need to send a DV? I have the funds on hand to pay the original OC if the debt is legit. I went to the ER twice last year, so this could be from one of those visits.
Here is a scan of the letter, and at the bottom is a scan of the account info they sent with the letter. Notice there is no date printed anywhere in the letter.

TIA for any help.