There's not enough information in the original post to understand what the $850 fee was for. But I can tell you that is not enough for a permanent residence application - so it's not clear what you mean by "in process."
If your application was not already submitted and you're looking at a future application, at best Allied would be helping you with finding an employer under a temporary work permit (from which you may become eligible for other programs) or the FSW arranged employment stream. And bickyii is correct, nursing is no longer a selected occupation for the FSW "occupations" stream...
I can't tell you if they are legit or successful. I can tell you that, depending on when you first "applied" for their services, nursing was on the select occupations list, but the FSW program was suspended last year, and the new list of preferred occupations released very recently by CIC. So the "delay" may not be Allied's fault. I can tell you that your application will go nowhere unless you get assessed and registered under the College.
I can also tell you that nursing in Ontario is an occupation that is currently under strain - Most facilities that hire nurses are underfunded for nursing staff, many nurses have a difficult time finding full-time positions (don't know if that is true for all provinces), and that many Canadian nurses go to the USA for jobs and better working conditions.
So - I'm not saying "don't do it," I am saying, be informed. You may wait a long time, and even if you were successful obtaining work permits, it will not be easy once you get here... You might want to do more research and possibly consider a different province...