You should consult your divorce attorney regarding the matter (or at least the person who drafted the divorce papers.) It is important that you file an Answer if a lawsuit has been filed before the company takes a "default" judgment against you which basically means you do not have a defense to the suit and are liable for damages. Typically, lawyers who handle such cases are looking to do just this, but are willing to settle the matter for less if you file an Answer. I would suggest you "third party" your wife and basically assert that the debt is hers and not yours. Nonetheless, without seeing the documents involved, it is hard to give firm advice.
Please keep in mind that this matter might have already affected your credit score as it could have been reported to the various credit agencies. You can find this out through the various free services online that will give you a copy of your credit report. Get all of this information together and provide it to your lawyer so he/she can assist you if your own efforts to not get the matter resolved. Do not waste any time, though, as you could lose significant rights, and bargaining power, if the company proceeds with the lawsuit when you are without an attorney who can help.