As for Chase and alleged delinquent accounts...
March 2011 several unsigned dunning letters from Frederick J. Hanna & Associates, P.C.
Timely DV letter sent to Hanna via USPS CMRRR.
April 2011 letter received on Chase letterhead stating "A thorough investigation was completed in response to your inquiry (presumably forwarded from F.J. Hanna to Chase) regarding your credit card account. We have determined that the account balance is accurate." Curiously that letter did not mention any account balance yet requested a payment be sent to a P.O. Box in DE. The bottom of the letter stated, "Account is owned by Chase Bank USA, N.A."
Nothing else until:
March 2012 a couple of dunning letters from ARS National Services, Inc. from their Escondido, CA office.
The second ARS letter included an offer to settle for 70% of alleged claim. (Seem to recall a much better offer direct from Chase long ago.)
Timely DV letter sent to ARS via USPS CMRRR.
No other response to date.