My only suggestion

before paying the $3,000 is go to the court and tell them "I was never served." "Please show me the evidence of service." If the facts are that you were never served, then I think there is a chance to vacate the judgment because you were not afforded a chance to defend yourself. Due process is guaranteed by constitution (even for non-U.S. citizens). You need your due process. That is what I would do.