Turn Png file into a Vector file that I can use to make a subliminated polo shirt.

I have a png file that is a picture of a polo shirt that I had made, I want to get more units of the shirt made so I need the shirt file to be amended to one that I can give the shirt company to use to produce a subliminated polo shirt - ie Vector file in correct format for shirt printing.
I need someone who has designed subliminated shirts before and knows what the shirt company requires.