Credit Card Lawsuit

In October of last year, I disputed a credit card debt on my credit report. It was listed under the original creditor, and that was the only record of the account on my credit report. They were unable to adequately prove the debt was valid, and it was removed from my report. One month after it was removed, a collection agency, claiming to be working on behalf of the original creditor filed a lawsuit against me for this debt. The suit is still ongoing, largely due to the fact that the collection agency had incorrect address information for me and was unable to figure out where to send the summons for a substantial amount of time. I never heard from the collection agency prior to the lawsuit, and they never appeared on my credit report. Can they really sue me after the item was removed from my report, and without contacting me regarding the debt? What recourse do I have?