Looks like you have been scammed. check out this link.
http://www.gnutellaforums.com/showth...threadid=28751
The basic version of LimeWire is free.
Contact your credit card company and explain it to them. Most have policies in place for situations like this.
I would uninstall that version and download it from the "official" LimeWire website.
http://www.limewire.com/english/content/download.shtml