First, anything paid to the US government is a processing fee - not an approval fee.
Second, paying for any fees other than a very few (like attorney fees which are for the work performed preparing the application) is illegal according to US immigration laws.
You are out of luck ! Next time, apply with a LEGITIMATE company and don't try to buy a US visa. Any demand by you will point out your illegal act, but you can report him to the USCIS.
If you had done any research, you would have known that your payment was not only illegal but foolish.