Did you buy Pro from www.limewire.com & did you pay $18.88 USD?
If you bought from the official site, you should've recieved a link to your personal download page...you can always go there & download Pro again

Or, you can go to the link below & enter the email address that you used to buy Pro
http://sales.limewire.com/support/pro_lookup.php

Just to let you know, if you didn't buy from the official site, your email address won't be in the database...you can't download a scam version from the official site.