@Nicola1863 "once payment was made to the host he sent an email saying we needed to pay 320 euro in cash upon check in". Are you sure this isn't a scam listing? You don't send money to a host on Airbnb- Airbnb charges the credit card you have on file with them and Airbnb holds that money until a day after the guest checks in. Hosts never have a guest's money until after check-in, Airbnb has it. And it's against Airbnb TOS for a host to ask you for cash at all.
And I don't quite understand- you say your reservation was for March 14th, which was 9 days ago, and you contacted Airbnb 5 days ago. Why didn't you just cancel the reservation before the 14th? A host doesn't have to "accept" a cancellation- you can easily cancel from your side, which is what you are supposed to do.(If you click on something asking the host to accept the cancellation, no knowledeable host will "accept", regardless of whether they are amenable to giving you a full refund or not- if a host clicks "accept", that is registered as a host cancellation, rather than a guest cancellation, and the host receives a whole lot of penalties for canceling) If you had cancelled before the 14th, you would have been fully refunded by Airbnb, as it sounds like your dates fall under their current COVID cancelllation policy. But since it appears you never actually cancelled, you might have to go through Airbnb to sort it out. And yes, they are really swamped right now, so you'll have to hang tight and keep at them.
If you haven't cancelled yet, you realize your reservation is still on the host's calendar, blocking those dates from being booked by anyone else? Totally unfair to the host. And if a guest put me in that position, I'd be unlikely to refund them anything.