GeoHoliday-Starpoint Timeshare Scam Phoenix, Arizona

We paid for our timeshare with our Discover credit card.  Tried cancelling over the phone a couple days after we returned home from Vegas and they said we couldn't until our account had been set up.  It could take up to thirty days we were told.  Well, by the time it was set up, it was too late to cancel, so we turned it over to Discover.  After a few weeks, $4000 was credited back to our account.  We were relieved and thought it was over.  One year later, we received a bill in the mail from Equiant, an affiliate of Geo Holiday that manages their membership dues.  I called Geo and asked what was going on, informed them that Discover had given us our money back and we no longer wanted anything to do with them.  They informed us that they showed our account was still active in their system.  Basically, we're are still haunted by these scam artists.  We may have gotten our money back, but apparently we are still responsible for membership dues for something like the next forty years.  I refuse to give these people my money.  An automated phone system calls daily to let us know that our dues are late.  We have outstanding credit and are planning on letting this go to collections.  We've never be in any situation like this before and are uncertain as of what to expect this to do to our credit.  Anyone that has any advice or suggestions are greatly appreciated.  I'm sorry for everyone who has been victimized by this company.