Generally, no. Big decisions regarding timeshare law are made in the Supreme Court. Rulings made in the Spanish Supreme Court set a legal precedent that then facilitates all cases in lower courts, meaning that they can be settled easily.
Where a timeshare contract is found to be illegal, it can therefore be declared null and void and the timeshare company ordered to return the ill-gotten payments received from the claimant. Once it is confirmed that a contract contains an illegal clause, the court does not even have to look at it before applying the law.
This means you do not have to go to Court unless your case is one that has never been seen before – in which case it will have to go to the Supreme Court, where there will be a much bigger legal battle and less certainty of success. However, the Spanish Supreme Court has now ruled on many timeshare law cases, meaning that it is almost certain that you will not have to go to the Supreme Court for your timeshare legal case.