Your letter referred to prior disputes under the FCRA, but clearly identified the letter as a request for debt validation under section 392.202, with specific reference to the deletion requriment under section 392.202(d)(1).
The debt collector, intentioanally or due to misinterpretation, treated the letter as a direct dispute under FCRA 623(a)(8), under which the implementing regulations at 16 CFR 660.4 permit them to dismiss the direct dispute as lacking in adequate information so as to enable them to conduct a reasonable investigation of your dispute.
The most prudent route would be to send them a clarifying letter, clearly stating that your prior letter was not a direct dispute under FCRA 623(a)(8), but rather was sent for validation under section 392.202 of the Texas Finance Code.
That would legally put them on clear notice of the intent of the letter.
However, you could alternately consider the letter clear, and treat their lack of compliance with the deletion provision of the Texas Finance Code as a clear violation of that statutue. Complaint of violation would be directed to the office of the attorney general for the state of Texas.
As for what you demand as necessary for validation, such requirments are not part of the Texas Finance Code, which requires only that they privide a statement that they "deny the inaccuracy." The code does not requrie that they provide the stated documentation in order to comply with the statement requirment.
Texas Finance Code, Section 392.202(b)
“Not later than the 30th day after the date a notice of inaccuracy is received, a third-party debt collector who initiates an investigation shall send a written statement to the individual:
(1) denying the inaccuracy;
(2) admitting the inaccuracy; or
(3) stating that the third-party debt collector has not had sufficient time to complete an investigation of the inaccuracy.”
