What should i do about an settlement offer for movies i didn't download

In a copyright infringement case, the loser pays the winner's legal fees.  You could litigate.   I'd also go search the term "copyright trolls", particularly looking at articles posted by Joe Mullin. The stories at least offer up one scenario under which you might be targeted without being guilty. Other than that, it is hard to give you advice without knowing what is in the letter and discussing it with you. Ultimately, you will want to see if you can get a consultation with an intellectual property attorney in Georgia who might be willing to represent you if you are sued.