My ex filed her response to my petition to modify childsupport. She chose the hand deliver option for serving me but never served me. I know she flied it because I can see it on the Web site. I went to the court house and got a copy. Can I file a motion to default if she doesn't serve me the papers with in the 20 days
Your question is not clear. If she hand delivered a copy to you she does not need to have you "served" by a process server.
If you got the documents then no you are not entitled to a default. That would be dishonest.