From my experience, you can have a default judgment overturned here in Nevada in cases of mistake, inadvertence, or excusable neglect (in other words, you have a good excuse). Whether the Court believes your excuse is a good one depends on a number of different factors. The good news is that, in the interest of fairness and justice, the Court generally prefers to try a case on the merits instead of issuing default judgments. That means that the Court overturns default judgments quite easily as long as there is not evidence to show that you should have answered the original complaint against your and appeared in court.
I recommend hiring an attorney to assist you if you are going to have the default judgment overturned.
If you did not appear at the small claims hearing, it is likely a judgment of default was entered.
Take your paperwork to a local attorney, hire him or her, and set a plan of action about how best you might avoid the writ. Too little information exists in your post to make a valid observation.