@Jieyun0, I'm sorry this has happened to you. I know of the changes that happened in Japan, and that so many hosts have lost their listings or are struggling to get that license.
1. Try contacting Airbnb support on Twitter, publicly. Specifically ask for a refund. I once had a terrible case manager who just refused to do anything, but I finally could get some help when I contacted the support account on Twitter several times. They tend to care more since the complaint is in public.
2. For your visa sake, it might be better to book somewhere else like hostels or hotels, while solving this issue.
3. This is for the worst case scenario: If you have paid with a credit card, check if the card has a travel insurance on it. Some card insurances cover cancellation of flights etc. that is not your fault.
I hope this gets resolved and you will enjoy the travel in Japan!
@Emiel1
As a person following this new regulation topic in Japan, I can say that the host most likely is bothered by this regulation to a significant degree, and it sounds that they are trying everything to get the license—although I think they should let the guests move on with their life. There are ridiculous rules to follow, and since this new law was enforced nationwide without providing sufficient trainings to city offices, unlucky hosts get an office where no staff knows what the heck you are talking about when you go in and try to apply for the license. Some hosts are saying they waited for 5 months+ even when they hired lawyers (and still didn't get it).
There's an English thread if you are interested. https://community.withairbnb.com/t5/Hosting/Japan-after-June-14/m-p/737839#M174076