NAF is being sued Class Action, largely precisely for this very reason. Get in on the Class here:
"http://milberg.biz/naf.html"
Also, about your present situation, file complaints with the BBB, the FTC, your State Attorney General, the Bureau of Consumer Affairs, etc.
If you already have a summons, then a DV letter will do you no good. What you need to do is file a Motion for Discovery. Call your local county civil court (or Google their website) for more info and the proper forms. (If it's not on the county website, check the state.)
As far as the other "judgement", call the court on that one, and file a Motion to Vacate due to Improper Service (since you never knew about it). It will likely be better to go in to the courthouse itself, though, because from what I gather, the telephone clerks can often be unhelpful.