Is aeroadvance legal in Mn.?

I had a loan through areoadvance over a year ago and somehow they just stopped taking payments. Then all of a sudden a couple months ago a I was contacted by a collection agency in New Jersey disguising as a lawyer by mail. Then someone called me in my hometown area and said he wanted to serve me papers if he could meet me somewhere or at home. He contacted my references also. I ignored the calls for a couple weeks and now it's been a month and I haven't heard anything. Is this payday loan company legal in Minnesota?