@Jessica2466 I'm sorry you find yourself in this position. But your failure to thoroughly read the terms of the cancellation policy of the listing is not a valid reason to receive a refund. When you book a listing, you are agreeing to accept the cancellation policy in place- it's a contract.
While many hosts would refund you the days they were able to rebook, they are under no obligation to do so, and it doesn't constitute being unethical nor taking advantage of your misfortunes for the host to uphold the cancelleation policy you agreed to.
Did you ever ask the host if they woukd be willing to refund any days they managed to rebook, or just go straight to reporting them to the BNB? (which will do you no good, as the host has not breached any regulations by not refunding)
While I am honestly quite sympathetic to you losing that much money, you just don't have a case here for a full refund.