At a guess, it sounds like the bolt is rusted to the inside of the bearing sleeve. Having had that experience, I always coat the bolts with anti-seize when reassembing. You didn't say what year, but if it were my bike, here's what I'd try:
1. Take off the shock & swingarm so that all you have left is the linkage rocker arm attached to the frame bracket by the frozen bolt. This would give you more room to pry, etc.
2. The next thing I'd do is get some good penetrating oil, like Kroil. Lay the bike down so that the threaded side of the bolt points up and liberally apply the penetrating oil. Leave it to soak for a few hours or overnight.
Then give it a few good whacks with a rubber mallet to loosen things up and see if you can pry it out. With the swingarm off, you should be better able to get in there and try things out.
Good luck.