Complaint Review: studypool.com

I searched online for several online tutor sites to see which ones could help with a particular subject that I needed help on. I found studypool, and I checked to see if anyone made a complaint on them. I found that the site was received with a high rating. I thought that it would be ok. I went to their site, and  I posted my work to see if anyone could help. I had three people bid on it. I chose a guy who promised that he knew what he was talking about. They instruct you to pay half of the fee upfront, and the rest after the tutor has completed the work. My mistake was not checking the work before I made the last payment. The tutor completely answered all the questions incorrectly, and they were blatantly bad answers that I could find immediately. I went back on their website to complain, and they sent me an email promising to refund my money through paypal. That was on 10/19/14. I have yet to receive a refund back. I emailed them continuously, and they would state at first that they would check into it. Now, they do not respond to any of my emails or phone calls. I am fed up with the lack of professionalism, and I feel like they stole my money from me. I continue to try to contact them with no response. I even went on paypal to dispute the charge, but I don't know how that will turn out. I don't know what other avenue to take this matter to. If someone has any information, please share with me.