This is a complicated issue and there are varying viewpoints and piskei halacha on the matter, just as there are in any issue but especially complicated ones.

Actualic is reporting on a psak from the beis din of Beitar Ilit regarding the issue of event halls that were set to host events - weddings, bar mitzvahs, etc - that had to be canceled or postponed due to Corona - what happens with the money from those bookings? People held weddings and bar mitzvahs on their porches and in their living rooms and in the streets instead of in the halls they had booked. It was nobody's fault - Corona did not allow it to happen as planned. it is not a matter of blame, but why should people pay for events in halls that did not happen, and on the other hand why should the halls lose out on the money for an event that was booked (and paid for, at least in part via the deposit) and they were willing to put on?

Generally, for the most part, people who contacted the halls to ask for their deposit back were turned away.

The beis din of Beitar Ilit sat to discuss the issue and has issued a psak as to what should be done in these cases. They dealt specifically with halsl in Beitar. The psak might or might not be similar for such issues outside of Beitar.

Regarding:
1. Wedding Halls:
The two halls in Beitar each operate differently, so the psak is different depending on which hall had been booked.
Regarding Ulam Hagefen, all money needs to be returned, partly in cash and partly in credit. Any monies over the amount of 2500nis should be returned in cash within 2 months. Any amount less than 2500 can be returned via credit to be used for another simcha (and can be transferred to other people).
If affected people do not have an opportunity to use the received credit by Elul 5780, the beis din will decide what to do at that point.

Regarding Ulam Golden Sky:
The owners rent the building from a landlord so in this situation they must return all monies paid above 1500nis within two months. the 1500nis itself is still up in the air and more information is needed for the beis din to rule on.

2. Regular halls
Other halls in town that are used for bar mitzvahs, sheva brachos, etc that are usually operated by various local institutions (shuls, etc) rather than businesses..
The hall management must return all monies paid within 30 days.
The sums paid in these types of halls are generally much lower, and any credit given will be difficult to use (presumably because new simchas will be booked quickly and will make the hall unavailable to be used for such credits).
Obviously, these halls cannot now cash any "head checks" they have already been given, nor can they try to collect any additional money for those events.

3. Regarding caterers:
The agreement with caterers is an agreement for providing a service. This is affected by what is categorized as "makat medina" - a countrywide plague - something that has affected everybody equally, and is also an "onnes", so the caterers must return all monies received.

4. Regarding transport arrangements (such as paid transport for schools):
These are considered service agreements and because they could not provide the service they cannot collect money for it.

However, because these transport companies have arrangements with the schools for the entire year, and base don those arrangements they invest in vehicles with significant investment (that often involve leasing vehicles, taking loans, etc), a compromise should be reached.

With both parties being damaged by the situation, the damages should be divided equally. Regarding the period that is normally Pesach vacation, the transport companies should be paid in full - every year they are paid for this period without providing service, so this year should not be different. Payment for other days should be set at 25% of the normal price.

5. Regarding School Transport arrangements:
Transport companies that do not work for the schools but via private arrangements with the parents
Some schools and institutions have their own drivers rather than outsourcing to a transport company. These drivers are like any other employee of the institution, and that issue has already been dealt with privately.

6. Day Care:
Day Care institutions working under the government arrangements must follow the instructions and decisions of the Ministry of Economics and Employment (that is responsible for day care). Their decision was that no money could be collected for the days the day care was shut.
These institutions have generally been compensated generously by the government and have received a majority of the monies they normally get.
They cannot collect any money for Pesach vacation either, that normally gets paid for, as such were the instructions from the Ministry.

7. nursery schools:
officially licensed nursery schools:
where the teachers were sent on employment furlough or those who were granted compensation (as freelancers), as long as they received payment above 50% of normal wages, the parents are exempt from paying any more for the shuttered months. For Pesach vacation they must pay as normal.

private gans:
for the month of Adar, full payment must be made. For Nissan, only payment for Pesach vacation should be made. For Iyyar, we cannot obligate people to pay, for numerous reasons, for the days on which no activity was held, but parents are recommended to pay 20% for those days.

8. Rentals of stores, yeshivas and institutions
if the rentals are for places that cannot be used for living they are exempt for part of the payments due during the months they could not function in a reasonable way. The landlords should deduct a significant percentage. If they cannot come to an agreement together, the beis din will make a decision in each relevant case.