The official site for downloading LW basic (free) or Pro is Lime Wire » Download LimeWire

People can buy Pro with either 6 or 12 months worth of updates & email support...there's no 'lifetime membership'. So, if you bought a lifetime membership then you must've bought LW from a scam site (there are heaps around).

Sorry, but you won't be able to download LW Pro from the official site, unless you pay for it.
If you like, you can download the latest free basic LW from the link at the top of my post

Membership? - **WARNING ** BEWARE** - Download p2p Clients ONLY Thru Official Sites