Shi-Long Lang

Nothing you need (or can) do...she's on her own to return home (or not and face the possible consequences).
 
If you ever petition another fiancee or spouse, they may ask what happened, in which case you would explain the circumstances. You didn't do anything wrong...it's completely on her to return home.

hi
 
nope, nothing to be concerned about, she stayed on her own, that's on her, she should have gone back.
 
that's not your problem

None. You did not marry, you did not apply for any AOS for her. She had the responsibility to leave the US on her own before the expiration of her I-94 she received when she originally entered on the K-1 visa. It's on her completely. Also, because she came into the US on a K-1 visa through you, she cannot adjust status in the US through anyone else. Perhaps she is unaware of this and thinking she can; but she can't.

If anyone is interested in what happened, the short version is... I won.
The long version... I contacted a congressman about the double payment, and they requested that I send any documentation I had. I sent every single document... my receipts, the letter telling me that I CAN pay online along with the date/time stamp... and the letter I received AFTERWARDS telling me that I CAN'T pay online with the date/time stamp. They investigated, and today I received a latter from both the congressman and the embassy saying that I will receive my money back for one of the payments.
However, the embassy's letter claimed that my fiancee did not provide proof that I had already paid online when she arrived at the embassy. I wrote back to the congressman thanking him for helping me in my situation... but also to set the record straight. I told him that the embassy's letter was incorrect. She brought printouts of my online receipt and a printout of the document saying that I can pay online... but the embassy refused the documents, saying that they do not accept online payments.
They should have just given me the money back from the beginning.

Thanks for looking out for me, Penguin_ie! I didn't know I had posted my full name. If you are talking about Shi-Long Lang... that isn't my name. It's actually a name of a somewhat obscure character in a somewhat obscure game: http://aceattorney.wikia.com/wiki/Shi-Long_Lang. My avatar is from the character as well. I couldn't think of a good name to use on the forums, so that is what I picked.
As for the double payment, the last I heard they are still claiming it is non-refundable. I understand that would typically be the case, but it seems a bit unfair to me to tell me that I can pay online, then tell me after I have already paid that they don't accept online payments. In order for my fiancee to go to her appointment, she had to pay a second time at the embassy I believe they need to update that message they send out once you complete the DS-160... it tells you to follow the link to find out how to pay for the interview, and the link says you can pay online. If they are sending this out with every completed DS-160, it will cause a lot of confusion!