How do you get rid of a timeshare scam you still owe on?

Hi, I am trying to find information. My wife and I bought into the Occidental First club at Xcaret near Cancun. Our original contract was biannual. Our first use of the vacation club was at Neuvo Vallarta. What we were sold and what we actually get are very different. Our original tour at Xcaret showed us their " First Club" area but it has been rebranded the "Royal club" and we cannot use it anymore. It appears the same is true for the area in NV. When they sold us the timeshare we were told they would buy it back if we decided we were not going to use it and apparently that is no longer true (if it ever was) unless we decide to upgrade to a more expensive package. They had also told us we could sell the week back to the hotel for the maintainance fees and a few hundred dollars extra. That is apparently also not true. We put down $6000 and have been paying the loan off in monthly instalments (~$10000 so far). We still owe ~ $9500. We have used exactly one "club" week and one "bonus time" week. What would it take to get out of this?