That is usually what happens when you go to a scam site and get LimeWire. My guess is yes you got scammed but not by LimeWire.
LimeWire basic is free to use as long as you want Pro is $18.88 for Pro and 6 months of free up grades there are no memberships or anything else.
The link below may help you of course if you believe LW scammed you then nothing is going to help you.
Membership? - **WARNING ** BEWARE** - Download p2p Clients ONLY Thru Official Sites