Can I reopen this court case?

I was convicted of a crime in 2007 (criminal damage to property). The case type is titled "Non-Traffic Ordinance Violation." Here's the story. I went to court in November of 07 and pleaded no contest and was found guilty of the crime. This is the wierd part. Three of my friends were also involved in the act. They were all found guilty as well. At the time of the crime (08-15-07), I was 16 years old. My friends were also of the same age. When we received our citation, the ticket was around $300. I noticed that my friends tickets were around 150 and found out that I was being tried as an adult (being 17 on September 7). So when we went to the courthouse we talked with the DA and he said I would be tried like everyone else in the crime, and reduced my ticket to 150. So now here we are 2 years later. I've recently applied for a job and was told I was turned down because of a criminal record. I searched on Wisconsin Circuit Court Access and found out I did indeed have a record with that violation. I then searched all my friends names and nothing came up. It's obvious that I was tried as an adult anyways, because otherwise my record would have cleared like all of my friends did. I just found this out now, and don't understand why this happened. It doesn't seem fair to me that when the crime was commited I was still a month from being 17, and yet they tried me as an adult anyways. I just want to know if a. I can reopen the case and b. if I could possibly be successful.