how to get out of my timeshare?

While on an exchange vacation in Cancun in 2009 we fell for the high pressure sales pitch from the Krystal International Vacation Club and purchased a timeshare. We were told that other companies associated with Krystal would rent our Krystal unit and sell our other timeshares to offset the cost of the Krystal membership. We paid the fees but our pre-owned timeshares were never sold nor was our Krystal unit ever rented. Our Krystal membership is fully paid and we have exchanged our Krystal unit for oher vacations through RCI, but we find the system cumbersome and are rarely able to exchange for a unit that we want at the time that we want it. I believe the entire timeshare industry is a scam and would like to get rid of my membership in the Krystal International Vacation Club.