Timeshare Exchange review: interval stole my one week of my timeshare I deposited with them

We are member of star wood vacation and the owner of Westinn timeshare in Hawaii. On 2010 we deposited our one week of timeshare ownership with interval international and they told us we can use it any time any year, but 2 years later they told us there is not point or any deposit week, then I called Starwood. They told us interval international charged them one week of the timeshare that we never used. Basically interval sold our one week to some else and lied to Starwood and us. if there is any class action against interval international we would like to join it.