I signed tax form 8332 for a friend who is not a relative of anyway to my child nor did they support my child or live with my child at anytime. I signed the waiver to help them pay less in taxes but later thought better of my actions and told them not to go through with filing to which they agreed. Then when I went to file I was told my daughters SSN had already been used and I could not claim her and would have to mail my return if I thought there was a mistake. I did not want anyone to get in any trouble for anything so did not pursue it any further but I am not OK with them claiming my daughter and want to claim her on my taxes as I provided 100% all year for her and she lived with me 100% of the year. What can I do to fix this horrible mess and set things right and what are the consequences for the parties involved??