You've been scammed.
LimeWire Pro costs $18.88 USD & covers you for 6 months of updates & email support. LW basic, just like FW, is free. I don't know what site you downloaded from but it wasn't the official LW site www.limewire.com. Therefore, your email address would never have been in the official database & of course, wouldn't be recognised

If you read through the threads below, you'll find some useful info
http://www.gnutellaforums.com/open-discussion-topics/28751-membership-warning-beware-download-p2p-clients-only-thru-official-sites.html
http://www.gnutellaforums.com/open-discussion-topics/44499-get-your-back-music-members.html

It's probably too late to get your money back now, but you could report this to your bank/CC company anyway. Keep an eye on your statements too, just make sure that no more "payments" are taken from your account.

*The official site for download of FW is http://www.frostwire.com/