What does you're patch puller look like? Sometimes, they call a bullet puller a patch puller - it's like a wood screw. There have been times when that didn't work for me, but a patch WORM did. They make different kinds, but mine was like two curved stiff wires going in opposite directions off the end of the attachment.
Here's a picture of another kind - top, third from the left.
If the patch is stuck AHEAD of the nipple, you might try a blast from an air compressor.

Good Luck