Silverleaf Resorts review: vacation package

About a year ago, I was called by a Silverleaf associate that I won a cruise deal. After attending the meeting, I was convinced to sign a vacation package. I tried cancelling before the 6th day but they kept prolonging the issue without resolving it. After couple of months around February or March; I was told to visit their other facility, I was told it is not a timeshare and how upgrading to a better package will be suitable. I later realize I'll probably not have any time to use this package, I called to cancel couple of times, no one picked up until I called via my Bank. One the day I called via my Bank, I was told by the Silverleaf Resort associate that I can sell it through Vacation Service Packages (VSI). I called VSI paid $300 for the vacation package to be sold at this time I was already defaulting in monthly payment. After trying all I can, knowing I can't pay for what I never used and will probably not be able to use, I stopped paying. Now Silverleaf Resorts has mailed me a Legal notice to pay off the whole amount. Please I need advice on what to do.