There is likely nothing to dispute. The contract terms control.
Timeshare Assessments Liens
What people often don't realize is that even if you're current in your deeded timeshare mortgage payments or the timeshare purchase price has been paid off, you could still face a foreclosure if you don't keep up with the assessments. Or you could also be sued for the amount of the indebtedness.
The rules of the timeshare are usually set forth in what is called the Declaration of Covenants, Conditions, and Restrictions (Declaration). The Declaration usually provides that if a timeshare owner defaults in the payment of fees, costs, and assessments, the entire unpaid assessed sum with accrued interest and other charges become a lien against the timeshare interest of the non-paying owner.
Can a Timeshare Be Foreclosed for Nonpayment of Fees or Assessments? | Nolo