No hay nada que rascar

[ROBINDESBOIS]

In English?
After trying to get something from somebody, after insisting on something and you realize there is nothing to do, you say.
No hay nada que rascar. (all context)

[EmpanadaRica]

Hmm well not sure about this one. :) Maybe:

' Oh well we gave it our best shot' ?
' There' s nothing left to do'

Or alternatively:

'We went the whole nine yards, but nothing worked/ to no avail'
(Something to this effect).

[Tomisimo]

There's nothing left to do.
There's no way to convince him/her/them.
They're not going to change their mind.
There is nothing more we can do.
We have no more options.