I hired a writer on these forums a month back to write a paper for me. I was given a quote of 560 and agreed to it because I had asked the person to write a couple of pages beforehand and was confident with her style. since then, the person has consistently missed deadlines, given me substandard work and not follow any of the requiremenrs I needed of her. yesterday, on Sunday, she emailed me the wrong paper and then threatened to email my university about plagiarism claims if I did not pay her. I told her about her mistake. she then insisted she would email me the paper by Tuesday and then proceeded to email.me on Thursday. the paper was substandard, full of grammatical mistakes, did not fulfill my strict specs, the references was not in order and one of the major subsections was missing. now she's insisting I pay 500 dollars because in her words "she wrote a complete paper". what should I do?