I agree. Hosting providers usually reserve the right to shutdown your server if it has been hacked, and phishing is often more directly harmful to people.
Many comments here take the phishing as "a fact", their terms might grant them the power to shut any server down but this is a threat I think every startup should learn if they use Rackspace Cloud or consider to. And we learnt that.
24 hrs is not just for respond to remove the content, it is also for the server providers to verify the complaint and react responsibly.
This would be analogous to, for example, AWS taking reddit offline because a user posted a phising link.
Nearly every web business which lets people put information on the web that others can see will face abuse issues at some point or the other - and cutting off a business and its legitimate customers because of one client misusing the service does not inspire confidence.