Your only potential option is to consider suing the roommate in Justice Court/Small Claims Court. There should be a Justice Court or Small Claims Court or Magistrate Court in your county. I recommend doing some reserach on that and going to the Court to talk to the Clerk and get some information about how to proceed on recovering this money. Some Courts have a limit, but the Clerk should be able to help you with that. Start here: http://www.nmcourts.com/othercourts/nmmagistratecourts.html
Best of luck!
NOTE: This response is general in nature and should not be considered legal advice. No attorney-client relationship exists or is formed by this response.