H1B Visa approved but not stamped

My H1B visa got approved in the last year (2014) but not stamped with my current employer. Can I now get this transferred to my new employer and get the visa stamped?

Can anyone help me,
My Previous employer had filed my H1B in 2012 but in between i left and joined another company. They withdraw my H1B and sent me withdraw notification letter. Now one of US based Immigration consultancy has contacted me and saying that they can file the H1B transfer but i have to pay the money. My question here is "

  1. Can we file a H1B transfer when petition has been already withdraw.
  2. In withdraw notice it has mention that the withdrawal of this case is a final action for which there are no appeal or motion rights. What it means…?
  3. Consultancy is asking money for processing and giving job opportunity. So is it safe…?
    Looking for quick response.
    Thanks in Advance