Urgent help please - how can we get a crowd funding payment recalled?

[ssd]

Dh paid an NHS crowd funding thing £500 by mistake, he meant to pay them £5

ARGHHHH

the bank said they can't recall it as its a crowd funding payment, even though the payment is seen as pending online

We're with Nationwide

Can anyone advise, I am on min wage and certainly cannot afford to lose £500

Gosh, I know!!! I'm trying to be magnanimous, I know it's a mistake but bloody hell
Dh is neither up nor down.