In all fairness to WP, if my blog got hacked the first person who would be feeling my wrath would be my hosting provider for having crappy security on my server. Quite frankly, unless you’re downloading stuff willy-nilly to your server (you’re not doing that, right?) your hosting provider should be providing enough security to protect you from random hacks.
As far as fixing your current problem, if all else fails I’d suggest going nuclear. Use the “export” function to create an XML file of your posts and pages, and delete everything on your server. Start over with fresh copies of WP and your plugins. And while you’re at it, look for a new hosting provider.