HELP! Filed taxes married filling jointly but not married in Nevada.?

Last year my boyfriend and I filed our taxes together at this little tax place hoping we wouldn't have to pay a lot to have them done. We weren't married (still aren't) and the guy filing out our taxes said we could file jointly. So we did, obviously we got more money then doing them alone. But we think he over charged us. We now have been living together for over a year almost 2 and have a baby together. So this year we decided to file them jointly again and did them online since they guy charged us more and when we did them online we didn't have to pay anything. Now I am trying to get Medicaid for me and my baby but they are asking why we filled jointly if we aren't married. We have been together for 4 years. What should I do?