Usually, in such cases, you should apply to the broker's regulator. But even if there is no such thing (which is unlikely, although if the broker is a scammer - it is possible), then ask for help in other forums, there may be a person with the same problem.
It seems to me that at times like this you have to fight to the last.
1. Gather all the data about cooperation with this company, make screenshots of correspondence, save your payment receipts, etc.
2. You have already been told about the regulator, but if it turns out that this company is illegal at all, you can try to contact the company that deals with forced refunds. But you also have to choose it correctly, you can find a lot of information about it on the Internet.