How to sell my Krystal Timeshare?

Last November we were scammed into purchacing a timeshare at the Krystal Poerto Vallarta. It was presented as an investment with assurances that they would be renting it back from us. we were told to sign the agreement that it was for vacation and not to worry about it as it was to get around Mexican law that did not allow Krystal to rent out the timeshare apartments. We have been complaining via email for months and have been offered bonus points and now no maintenance fee for the first year. We are frustrated as we do not take regular vacations and just stand to lose