Sorry to tell you this but you are posting in the wrong place. You are right you were scammed but no by LimeWire you were scammed by the people that charged you for a free program. LimeWire basic is free and pro cost $18.88 which entitles you to 6 months of free upgrades. My advice to you is get in contact with your credit card company and try to get your money back tell them you were scammed and you might have a chance.
Making threats here will do you no good at all LimeWire is not the ones that scammed you. The link below will take you to the official site where LimeWire is free. Good Luck
http://www.limewire.com/