Tell them to immediately stop calling your work. If they were a legit debt collection agency they would have to comply or you could sue. However, this is not a legitimate operation. They will continue to call. Just let your boss, admin, whoever know that this is a scam and ignore all calls and block if possible.
Its a scam. Also when they give you an e-mail address to send documents (proof of debt paid, etc) it will put a virus on your computer, so don't try emailing them.
Called today (6/25/15) stating that there was a very serious problem with my name and social security number and I needed to update my information immediately.
Guess they think I just fell off the "turnip truck"!
They called my mother who i use on all my information and the lady Said her name is Nicole Mathis with Johnson & Johnson and they were calling about a legal matter.