DO NOT IGNORE!
THEY WILL TAKE YOU TO COURT.
I never received anything in the mail and they still were able to freeze my bank account last year and I had to go to court to fix everything.
Call them.
If the debt is not yours be prepared to prove it with documentation and you will not be liable. If the debt IS yours don't promise to anything you cannot keep up with, but see what you can work out though because if you ignore things like this it can get really bad, I know I've been there the past few years.
