You probably don't even really have a case yet. Do you have a copy of the Complaint? Is the cause for the Complaint legit? Do they have competent witnesses, or just attorneys passing on unrefuted hearsay? Am I speaking Greek to you?

Learn Greek.
If you don't have time to defend yourself, (i.e. spend a few sleepless nights in front of your PC learning how to win this battle) then you will lose. It's really a matter of how you prioritize your life. It least it has been for me. A few sleepless nights beats the heck out of years of paying off debt needlessly. Your decision.
Anyhow, here are a couple of cites on 'void judgments' and 'jurisdiction' which you should know. If you don't understand those two terms, you should not step into the arena at all. Just do a search on this forum of an online legal dictionary to get a handle on terms. You might be surprised how quickly you can come out of the fog... And do a search on this forum for "Cornforth", download the videos at the link you will find, and stop the world for six hours. If you really want to win.
You also owe it to yourself to read the Fair Debt Collection Practices Act and see if it might apply to your situation. I am sure it does. In my experience, the Civil Warrant for alleged money due actually contained a clause from the FDCPA that debt collectors have to display when collecting a debt. This allowed me to incorporated the FDCPA in my favor, and use it to make them obey the law.
A debt which has not been validated, is (ta da...) NOT VALID. So any determination made by a court on a debt which is NOT VALID, is at the least questionable. At the best not enforceable. (i.e. Void). It's a bit like only hearing one side of the story in a dispute, and then making the best decision you could with only half of the facts. If you don't present your truth, theirs will always prevail. And you will pay for dinner. When they could BE dinner.
Cases on Jurisdiction and void judgements:
"Either a judgment is valid or it is void, and the court must act accordingly once the issue is resolved." In re Marriage of Hampshire, 261 Kan. 854, 862, 934 P.2d 58 (1997).
"A judgment is void if the court acted in a manner inconsistent with due process. A void judgment is a nullity and may be vacated at any time." 261 Kan. at 862.
"A void judgment is one that has been procured by extrinsic or collateral fraud or entered by a court that did not have jurisdiction over the subject matter or the parties." Rook v. Rook, 233 Va. 92, 95, 353 S.E.2d 756, 758 (1987)
A judgment obtained without jurisdiction over the defendant is void. Overby v. Overby , 457 S.W.2d 851 (Tenn. 1970).
A void judgment is one of the grounds for relief under Rule 60, Tenn. R. Civ. Proc. See Rule 60.02(3).
In a criminal proceeding lack of subject matter jurisdiction cannot be waived and may be asserted at any time by collateral attack.
[U.S. v. Gernie, 228 F.Supp. 329 (D.C.N.Y. 1964)]
Jurisdiction of court may be challenged at any stage of the proceeding, and also may be challenged after conviction and execution of judgment by way of writ of habeas corpus.
[U.S. v. Anderson, 60 F.Supp. 649 (D.C.Wash. 1945)]
"The law requires PROOF OF JURISDICTION to appear on the Record of the administrative agency and all administrative proceedings." Hagans v. Lavine, 415 U.S. 533 (1974)
"Therefore, it is necessary that the record present the fact establishing the jurisdiction of the tribunal." Lowe v. Alexander 15C 296; People v. Board of Delegates of S.F. Fire Dept., 14 C 479
"A Justice's Court is an inferior court, and its jurisdiction must be shown affirmatively by a party relying upon, or claiming any right under, its judgments." Jolley v. Foltz (1867), C. 321.
"If any tribunal (court) finds absence of proof of jurisdiction over person and subject matter, the case must be dismissed." Louisville RR v. Motley, 211 U.S. 149, 29 S.Ct. 42 (1908)
"A judgment is absolutely void if it appears that there was a want of jurisdiction in the court rendering it either of the subject matter or the person of the defendant." Hahn v. Morse (1868), C. 391.
"An officer who acts in violation of the Constitution ceases to represent the government." Brookfield Const. Co. v. Stewart, 284 F.Supp. 94.
"Judges not only can be sued over their official acts, but could be held liable for injunctive and declaratory relief and attorney's fees." Lezama v. Justice Court, A025829.
"Our own experience is fully consistent with the common law's rejection of a rule of judicial immunity from prospective relief. We never have had a rule of absolute judicial immunity from prospective relief, and there is no evidence that the absence of that immunity has had a chilling effect on judicial independence." Pulliam v. Allen, 466 U.S. 522, 104 S.Ct. 1970 (1984); cited in Lezama v. Justice Court, A025829.
"Judge acted in the face of clearly valid statutes or case law expressly depriving him of (personal) jurisdiction would be liable." Dykes v. Hosemann, 743 F.2d 1488 (1984).
"In such case the judge has lost his judicial function, has become a mere private person, and is liable as a trespasser for damages resulting from his unauthorized acts."
"Judge's honesty of purpose and sincere belief that he was acting in discharge of his official duty was not available as defense in action."
"Where there is no jurisdiction there is no judge; the proceeding is as nothing. Such has been the law from the days of the Marshalsea, 10 Coke 68; also Bradley v. Fisher, 13 Wall 335,351." Manning v. Ketcham, 58 F.2d 948.
"A distinction must be here observed between excess of jurisdiction and the clear absence of all jurisdiction over the subject-matter any authority exercised is a usurped authority and for the exercise of such authority, when the want of jurisdiction is known to the judge, no excuse is permissible." Bradley v.Fisher,13 Wall 335, 351, 352.
"The immunity of judges for acts within their judicial role is beyond cavil." Pierson v. Ray, 386 U.S. 547 (1967).
"Ignorance of the law does not excuse misconduct in anyone, least of all in a sworn officer of the law." In re McCowan (1917), 177 C. 93, 170 P. 1100.