Legal Question in Credit and Debt Law in California

I would suggest first contacting the court and get copy of documents that were filed as proof of service and see what is on file. You can file a motion to set aside default, but you would have to challenge the service in this... You will have to overcome the presumptions and claims to proper service...If you owe the debt, and you do challenge it, it may only delay the inevitable and increase the costs...

You will not be successful without an attorney. You also have six months- max - in most cases to ask that it be set aside.