I'm curious. Did you use a regular ratchet, breaker bar, etc (how long was the handle)? Did you use more of a constant pulling pressure or short bursts/tugs? Maybe you can weld something (nut) onto the stripped bolt to give you a new gripping surface. Can you post up a pic of the bolt so we can see how badly it is stripped? Maybe it still has something to work with...could have an idea or two for you.
i used a small torque wrench (only b/c it had a longer handle) and a 12 sided 24mm nut. I know, should've used a 6 side, but couldn't find one anywhere and figured it would strip anyway. Will post a pic but am about to leave for the week so i don't get to attempt anymore till next monday. Will post pics then. i'm thinking getting a 23 mm socket and hammering it on. the bolt still has some side on it.