Don't give up yet. Try tightening the bolt slightly before attempting to loosen. Sometimes this is just enough to break the bond of a stuck bolt. Pour boiling water on the crank around the bolt area trying not to heat up the bolt itself before trying to loosen it. Give the bolt head a wack with a hammer and punch. Down the list a bit would be to drill the bolt head off and use your puller to get the crank off which will give you enough of the bolt to grab onto with some vise grips (it might come out easy as well with no tension on it from the crank) and you can save the BB and crank.