I've been contacted by over a dozen 24 Seven recruiters over the course of the last few years and not ONE of them has ever replied to my confirming I'd like to talk with them about the role they're recruiting for. If someone has the time to initially contact candidates to schedule interviews, they also have the time to send a quick note back if there's been a change of plans, and not leave the other person and their hopes hanging. Makes one question the validity and professionalism of the whole company when the same thing happens with every single employee you've interacted with.