I don't mean to offend, so, if you've already done this, I didn't mean to imply anything...
Anyway, have you tried doing a complete uninstall of the game? (i.e.: using the game's uninstaller, then going in and making sure that not one single folder remains from its previous installation.) Presumably, if you uninstalled it, and then reinstalled it from the CD (can I go out on a limb and say that you do have a CD...) it would be back to the way it was -before- the patch that (presumably) screwed it all up.
Hopefully that'd fix it for you... I'm suprised their tech support won't do anything for you in this instance...