Hello all. I know nothing about graphics or design, so please bear with my newbie questions .

I have a .png file which I would like to use for my business card. The business card supplier needs a 'vector-based PDF' of this PNG file. I have both Imagemagick and Inkscape installed but cannot work out how to convert it. Do I need some other software or can you point me to how to do it in either of these applications? Thanks very much.