Legal Question in Credit and Debt Law in Texas

If it's been at least four years since you last made a payment (or promised to pay), you can plead the statute of limitations. Heck, I'd plead it anyway, just in case.

And if you're being sued, you should get a lawyer. You'll want to send them pre-trial discovery. And you'll want to answer the request for admissions that they have almost certainly served on you.