Writers guess and write random words. There is no substance, and zero effort made to requested content of the assignment. If you provide them with PowerPoints, or printouts to read - they don't even look at it. Every paper I have requested has to go through 3-8 revisions as the papers are completely off topic and not even what I asked for.
Don't waste you time or money because he amount of time and effort you spend on reviewing and requesting revisions, you could have just written it yourself.