It won't change its name. The reason they are still in business is that they are so dirt cheap. They are known in the area and avoided by almost everybody except for these "tours" and the uninformed.
> But perhaps worse that that, a hotel behaving like this, and not being slapped down hard by the Tunisian authorities, will damage the entire Tunisian tourism industry
It's already damaged. The tourism industry is a joke and the receipts are laughable comparing to other countries (Morocco or Egypt). Just a week before protesters were able to blockade a main road in the capital and cause a gridlock for several hours lasting until late-night.
Protesters cause gridlock in countries like England, Germany or Canada too. (Google for Uber-related taxi protests.)
Holding someone "hostage" like that, can be a pretty stressful event for anybody. You put some claustrophobic people into that situation and we've escalated things to traumatized. A traumatized person could easily blow this up into vendetta.
"The detention of a customer by a business owner (e.g., hotel operator, apartment owner, credit card company) for the failure to pay a bill."
The closest parallels I can think of are the "mechanic's lien"[0] from English Common Law, or "debtors' prison"[1].
[0] https://en.wikipedia.org/wiki/Mechanic%27s_lien#Creation_and...
I would say that the facts presented above answer that question for you.