OOOH Boy, so much to say. I'll keep it short.
They probably have not told you everything. Look at the founder of this "Religion", look at the changes that have been made, look at the old material that they don't want you to see. Anything and everything in the Bible can be perceived at least two ways. Alot of what they teach is not scriptual. Add this to a doctrine such as their blood doctrine(which is changing as we speak)and you get nothing but a CULT.
Ask if its true that Russell used pyramids to come up with dates, ask if the Judge said that millions living in the 1920's would never die. Ask what will be different once you are "baptized".
Ask them to show you proof that Jesus returned in 1914. Ask them to show you that Jehovah picked them to be the "slave".
Ask them if you can be "saved", using all of their beleifs, but not be part of the organization.
Better yet, find the answers to all of those questions here. I also recommend http://quotes.jehovahswitnesses.com/ .
The JW's are VERY believable. I ask this, Have you ever been a member of a religion? What got you involved with these people?
Break the chains that bind you,
unless, of course, you're into that sort of thing.