Well, I had made a mistake and trusted on someone who I did not know well.
He was a Korean PhD student and we were working at the same building. For some reasons he asked for some money and I just simply trusted him. After some months he dropped his studies and went back, and since then he does not responding to the emails.
A lifetime lesson learnt, but what can I do now?
Besides the money, I feel offended and am ashamed of myself that how simple am I!

I have a record of the emails, about the money, and the bank transfer. But what can I do?
Thanks.