Yes I would 1 2 punch them.......but maybe with the DV2 letter (in the dispute letters thread).....letting them know that they have NOT provided validation and that they are currently in violation........and if you do not receive proof of debt you consider the matter closed.
You already have them on one violation........so just keep a good papertrail.
When it comes down to it, you will have some leverage so you can get it deleted.