single-cat,stp,wal-mart, help!

I paid not a little amonut money to a guy by paypal for some products one month ago but now i find that this guy is cheating me,no products recieved and no response from him(I used to successfully by using the same way for the first time).Some of the money which i paid him is cash in my paypal account and most of them is taken from my visa card by paypal. These money is really important to me :( I sent a email to paypal and they open a case for me then let me wait so do i have chance to get money back? Could you tell me what can i do now?How can i get my money back? Thank you very much for your help.