I brought a girl to the usa on a k-1 visa and married her. now i need advice?

i brought a my filipina fiancee to florida on a k-1 visa and married her in may 2008. obviously i was her sponsor. by janurary the relationship ended(she used me to come here, it turned out she never really wanted to be a wife to me). i have written several letters to uscis since then(sent registered mail) explaining that i felt that she used me for immigration purposes(i had proof and witnesses and offered to send it to them) and that we are not together any more and i oppose her staying here. and that i dont want to sponsor her any more. and i always give them my phone number and email address and mailing address and ask them to contact me letting them know how to make sure my name is withdrawn as her sponsor and her financial support or to let me know what i need to do for that to happen. but they will not reply or respond to me. fortunately i signed an ironclad prenup(yes, she had her own attorney review it and explain it to her before she signed it) before we got married that says she cannot get support or any lawyers fees paid in the event of a seperation or a divorce. we have both signed ''uncontested'' divorce papers. and i have them in my possession but i have not filed them yet because she is the one who needs to be remarried in order to stay here, so i told her she needs to be the one to pay for it, she scammed enough money from me when we were married that i wont spend another penny on her. anyway, my first question is: what can i do to get uscis to make sure i am off of her paperwork? and i understand in two years they will review her visa to see if she can stay here or not. every month like clockwork i send uscis a letter(just so they understand i am not going to go away) making sure they know i feel that she married me under false pretenses for immigration purposes, that i oppose her staying here and i would like to testify against her when the 2 years is up. my other question is: can she still stay here and get her citizenship when the 2 years is up? and does it matter if we are divorced and she is remarried as far as her getting to stay here. the honest truth is i loved her a great deal when we got married, i did not know she did not want to be a good wife to me until it was too late. i learned that a girl who wants to use her god given beauty to deceive a mans heart can do so pretty easily, no matter how smart the guy thinks he is. and her deception caused me a lot of financial and emotional harm. i would appreciate all advice on the matter. thank you