Were you arrested?
If you weren't, then it's not a charge. If it's anything, it would be a tort case (for money damages).
Don't be afraid of calling them up and telling them to tell you exactly what is allegedly going on. Don't let them sweet talk you into going there or getting a free consultation or any other such crap. If they have court documents, then you want to see them, here's 50 cents per page for your troubles.
Either they're full of it and just trying to get your business (possible), or they have stuff which the state of Indiana hasn't yet entered into their online system (this can happen).
You're entitled to a copy of any lawsuit against you.
And as for any nonsense you've seen on TV or in the movies about people ducking service of process, that doesn't do you any good and it does not help your case (if there actually is a case). Why? Because you'll just be hit with a default judgment against you, and will have to hire a lawyer to unravel it anyway.
So tell them you want to see the papers.