Actually, no they generally won't just send out another form if you call. You can use whiteout and hope that does the trick, or you can not return the form and they'll send out another.

Personally, I'd return the one you've filled out. Did you fill it out in the most ideal way? No. That doesn't mean you'll receive the Long Form though. And even those that fill out the short form in a way that causes no Long Form triggers, 5% still receive it.