File an answer with the court. Deny that you owe the amount claimed. Deny anything else that you disagree with or that you are unsure is true. I assume that you are making payments through the attorney's office that filed the compaint. If not, you should be. When you have paid what is owed, which likely will include the court filing fee and the sheriff's fee for service you, the attorney will dismiss the complaint. You also want to make sure that the attorney files a dismissal of the notice of lien filed in the Registry of Deeds.