No CVV , no show how can the host take the accrued money then?

Hello everyone .

I had  a policy reservation of  free cancellation before one day on arrival  , then all the money will be charged .

I had a guy who did not cancel his booking before one day , then I understand that he will come .

But he did not cancel , then his booking should be charged with full money , when I opened his Virtual credit card ( the moment that booking allow me , it was not with CVV number ), I pressed a buttom of invalid card , they told me will ask the guest for cvv in two hours , Later on  he did not give it  to booking , and I report him as no show , But in such cases how we can deal with charging the full price ? 
And  how he could book with no CVV on booking.com .

Many thanks