Ex filed motion to set aside judgment of divorce

I was finally granted my divorce after my ex tried to drag the process out as long as possible by asking for extensions and then a court hearing and then never showed up for the court date. Now, over a month later, my ex has filed a Rule 60 Motion for the judge to set aside the judgment. How is this even possible? Under what circumstances would a judge reverse a divorce? Why would the courts allow my ex to continue to legally harrass me and try to keep me hostage? What are my rights? Please help, I was given notice yesterday and the hearing is on Monday and I do not want an extension, I want this over. Thanks.

update* I found out that the courts messed up and set up two trial dates for the live divorce hearing which is why my ex is trying to overturn the divorce. What are my rights?

It is difficult for me to answer your question without reviewing the court file and knowing what happened. It would seem that even if there were two court dates, if the one you attended was properly scheduled and noticed that it should stand. If it does not, reset the court date, and get the divorce entered again. It should be a fairly simple and quick process if you have already filed the divorce complaint and the time to respond to the complaint has passed.