@Timothy412
I am sorry about your situation but, if I were you, I wouldn't waste more time trying to get assistance from Airbnb CS because you don't really have a case here.
Early on in the pandemic, Airbnb was issuing refunds to all guests who had to cancel due to COVID related issues, but this has not been the case for a very long time. Those refunds only apply to bookings made before 14th March 2020. The reasoning is:
"Our extenuating circumstances policy is intended to protect guests and hosts from unforeseen circumstances that arise after booking. After the declaration of COVID-19 as a global pandemic by the World Health Organization, the extenuating circumstances policy no longer applies because COVID-19 and its consequences are no longer unforeseen or unexpected. Please remember to carefully review the host's cancellation policy when booking and consider choosing an option that provides flexibility."
Now, I don't know what technicality is preventing you from going on your trip, as you haven't specified that, but it is your responsibility to check the cancellation policy and any relevant travel restrictions/requirements. Even if you can't complete the form before booking flights and accommodation, surely you were able to see what was required?
If your travel insurance won't cover you due to this mistake, then why would you expect the host to act as your travel insurer instead?
Personally, I would refund a guest if they cancelled within 24 hours, providing the booking wasn't last minute. It is a shame that your host went back on his promise to refund you should the nights be rebooked. However, technically, he is not under any obligation to do so. He has a right to stick to the cancellation policy that is stated on his listing and which you agreed to.
Sorry to be the bearer of bad news, but that's just how it is and would explain why you are not getting anywhere with Airbnb CS.