International Student Tax Return

Hi - I am an international student studying in Washington State, and I used Turbo Tax to file my taxes. However, after getting my return back, I found out that I was not supposed to use Turbo Tax since I am not a legal resident and I have been here in the US for less than 5 years. What should I do to amend these mistakes? or who should I contact to fix this situation? I would kindly appreciate your help.