This happened to me with a spanish last year. I tried everything, until I managed to tap it out by drilling a groove into it, then using a flathead and a hammer to bang it out of the frame.
If you're really desperate, 'Plan C' for me was to drill it in half (2 places) then just pulling it out with pliers. Never had to resort to it, but a guy at a shop said it worked for him.
Edit: sorry, forgot to add. Rust penetrant was essential in getting it out. Without that, I don't think it would've ever came out. You literally have to spray it anywhere you can and tap it with a mallet afterwards every 15 minutes for hours on end.
Or you could just soak it in gasoline. I've heard that works too.