The only other possibility I can think of for you, and to be honest it probably won’t give you good results (but you could try it), is if the logo only has a couple, solid colors in it. You may be able to use Keylight to key out each individual color of the logo. You’d probably have to do a lot of tweaking and even then I have doubts as to how it would look, but you could give it a shot.
Like Dave says above, either reshooting or rotoscoping is probably your best bet.