Of course it's illegal. Workers in any industry have the legal right to take vacations, which is only the particularity of catering and accommodation services. In fact, your right to take a vacation has not been met. If you don't have a rest, they can claim compensation and arrange employees to pay three times their salary on national statutory holidays.

Although the labor law is the worst of all laws, it does not mean that it has no deterrent effect. If the hotel goes too far and doesn't give you rest or money, then go to your local labor inspection brigade through the local area and complain, and they will handle it.