First of all, where did you buy Pro from? The only official LW site is www.limewire.com. LW Pro costs US$18.88 for 6 months of updates & email support, LW basic is free.

If you bought Pro, you shouldn't be being prompted to upgrade to Pro!! There are no popups like this in the Pro version. You said that you "paid the extra amount to recieve Pro".... sounds like you've been scammed.

If you bought from a scam site then, of course, your email address won't be in the LW database.
You should contact your bank/CC company & report this. Please read the 2 threads below, if you have any questions then post back here
Download p2p clients ONLY thru official sites

Get your $ back music members