Most hosts will take the site down once they've been notified.
If they don't, kindly send them an email telling that that because of the Digital Millenium Copyright Act, hosts are held directly responsible for copyrighted material.
If you still don't see action, post both your emails at
www.webhostingtalk.com
The people there are great at flaming, and you'll be almost certain that your host will remove the account or risk loosing almost all their business.