i bought two images of a Star Burst to open in photoshop and the transparent background isn't transp

if you are planning to use it in a composition and could not find transparent background, try searching for any star burst with black background and place it on any image you want to, then  use "screen" blending mode it will hide the black background.

otherwsie, I would recommend using a third party plugin in called Knoll Light factory for photoshop where you can create your custom made star burst.

I would contact whomever you bought them from, as they weren't saved properly. Was that the format in which the files came?