If they are claiming additional amounts then you have every right to dispute the claim. You can file a dispute with the three credit bureaus, you can send a FDCPA dispute in writing to the law firm handling the account, and if a suit is filed (doubtful) you can argue res judicata that the account has already been sued upon. Good Luck.
You should also check into your states version of the doctrine of Full Accord and Satisfaction and if the lien was paid in full, you should check into your states penalties against creditors for not filing a satisfaction of the judgment lien within a prescribed period of time after satisfaction of the lien. You definitely should consult a local attorney concerning your options.
This answer expresses only general statements about bankruptcy and/or debt defense and does not constitute advice to you in any form and does not create an attorney client relationship between the party asking the question and the party providing the answer. Furthermore, all cases are fact specific and it is not possible to give you legal advice without a complete evaluation of your case or if you are already represented by an attorney. Therefore, this answer does not constitute legal advice of what you should do specifically in your case. You should seek local counsel to help you with your specific issues.