Odesk is "one sided" with no transparent policies

I spend my money, time and effort, when I offer a job to candidates and they take jobs, though they do not know what they are doing, just by saying I will do that and I know to do that and show so examples of relevant work done. After I hire them, either they don't respond or they ruin the work, just by doing something they know and not related to the job description. Here comes, "Odesk" part, I leave a feedback for whatever "frustration", I went through because of the freelancer, they see the feedback and simply refund the amount I paid to them and "Odesk" removes the feedback. Simple, again the freelancer will have old ratings with "5 stars" on their profile and freelancer can play again with a new client. I understand that freelancer refunds the money and Odesk removes the feedback from user profile, but who will pay for the "frustation" and "dissatisfaction", I went through by hiring the freelancer? and who will refund the "time and efforts" I lost by running after the freelancer. I request Odesk to change their one sided policies to protect freelancers by removing their low ratings, moreover it is the client who is paying the money not the freelancer. I had the same issue with more than 3 freelancer, as I hired them by seeing their 5 star rating, may be Odesk might have removed their low ratings with their past clients. As soon as I hire them, they just spoil my project....