I really don't see how.
They file a case. They present an argument. The other side doesn't. What should the court do? Keep asking the other side to bother to show up? If they did that you could block any claim forever by just not showing up. That's not justice.
Our whole society's legal basis is 'show up and present your case and have it judged'. It's called the 'adversarial system' - look it up.
If it's a genuine debt, and it sounds like it is, then either pay up or argue your case in court.