WRITE to the credit bureaus (a paper letter - lick a 44-cent stamp) and tell them the whole story. Demand that they remove the false information from your credit report.
And then go to the court where the lawsuit was filed and look at the court's file (you might call first and tell them you're coming). Look at the RETURN OF SERVICE that shows that you were served with the lawsuit. You may have the right to file an equitable bill of review even though the time limits for appeal have passed (you'll need a lawyer for this).
